Citation
Conversion tables and equivalents for use in work relating to insect control

Material Information

Title:
Conversion tables and equivalents for use in work relating to insect control
Creator:
Nelson, R. H
United States -- Bureau of Entomology and Plant Quarantine
Place of Publication:
Washington, D.C
Publisher:
U.S. Bureau of Entomology and Plant Quarantine
Publication Date:
Language:
English
Edition:
Rev. ed.
Physical Description:
21 p. : 27 cm.

Subjects

Subjects / Keywords:
Weights and measures ( lcsh )
Insect pests -- Control ( lcsh )
Genre:
bibliography ( marcgt )
federal government publication ( marcgt )
non-fiction ( marcgt )

Notes

Bibliography:
Includes bibliographical references (p. 20-21).
General Note:
Caption title.
General Note:
"May 1952."
General Note:
"E-517, revised."
Statement of Responsibility:
by R.H. Nelson.

Record Information

Source Institution:
University of Florida
Rights Management:
This item is a work of the U.S. federal government and not subject to copyright pursuant to 17 U.S.C. §105.
Resource Identifier:
030271281 ( ALEPH )
18994116 ( OCLC )

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Full Text
LIBRARY
TATE PLARY PA3ARD E-517, revised

United States Department of Agriculture
Agricultural Research Administration
Bureau of Entomology and Plant Quarantine

CONVERSION TABLES AND EQUIVALENTS FOR USE
IN WORK RELATING TO INSECT CONTROL

By R. H. Nelson
Division of Stored Product Insect Investigations



Contents
Page
IAS St cui RM ee ey okie G's, 0, 0, fn nia bag eine 2
Capacity - liquid - measure. REMY ies). oy, 0, iota yay oes 3
Equivalents for teaspoonful, tablespoonful, and cup. 5
Capacity - dry measure. : 5
MiG Wemagiire amd CUDLC IMECAaSUTE . . 24 6 6 5 s+ eis es ow ww 6
Primm antsecticidal Chemicals ..... ++ ss : 9
Equivalent quantities for various Ge ateres of ater 2 oat 9
aa Concentration on the basis of percentage of toxicant 9
Concentration expressed in parts per million. Le
Dosage equivalents and relationships . 13
Dusts.and soil insecticides ; 13
Weight-volume relationships in ee seiner oes ni 16
eee mnt ates 1Oi KOW CrODS 0... 42, «2. %. +) +) s 0-0 ee yz
Pier OMO NG ee bs eile a ie ee es awe 17
Miscellaneous 6 Ae 19
Capacity of eee cae Se, ake eee ie
Peano etaiscinie liqgids by volume .. .. .. +. + ++ +6 19
WeeaarertateIGe PC OMVEL SION 05 66 2 an se ) se ee wk te ew we tee 60
Sb dil acetal

mnie OU es a ee os sks esas ye ss oele 0 @ 0 6.8



AD

In the literature on economic entomology the weights and measures
used in expressing concentrations and dosages of insecticides may be in
one or more of three systems--the United States, the imperial (British),
and the metric. Since information on the relationships and equivalents
in these systems is not always readily available to entomologists in the
field, it has been assembled here for their benefit. The data on equiva-
lents are taken principally from publications of the National Bureau of
Standards (4, 5) and the International Critical Tables (6). A comparative
discussion of United States and British units by Bearce (1) and a paper
by Irwin (3) were sources of valuable information. ai

Tables of equivalents for use in diluting insecticides, methods of
calculating concentrations on the basis of active ingredients, and certain
other miscellaneous information useful to entomologists working with
insecticides have also been included.

The measurement equivalents are carried out to sufficient decimal
places to furnish accurate figures for precise laboratory work. They
can be rounded out at the decimal place best suited for the equipment
of the individual worker. The concentration equivalents have been
carried out one to three places. In recommendations for practical use
it is suggested that values be given as whole numbers or in steps of
one-half wherever possible without gross error.

MASS

The basic units of the United States and British imperial avoirdupois
systems differ in definition, but are equal for practical purposes. There
are certain differences in terminology between the two systems that
should be noted. A stone of the imperial system is 14 pounds. That
system also uses 112 pounds as a hundred weight and 2,240 pounds as a
ton. The hundredweight of the United States system is 100 pounds and
2,240 pounds is called a long ton. The latter unit is also the gross ton
of maritime commerce, being criginally based on an estimate of 12
pounds of container per 100 pounds of commodity.

The apothecaries and troy weight systems should not be used in
entomological work, and fortunately their use elsewhere is dwindling.
Except for the grain,yhomonymous units in these systems and the avoir-
dupois system are not equal.

The metric ton is sometimes referred to as a millier or a tonneau,





~

Units of Mass



Metric





U.S. andimperial avoirdupois

|
igerain(gr.) 1 1/7000 Ib. 64.798918 milligrams(mg,) |64,698.918 micrograms



! (Aug. ory
1 dram (dr.) {| 27.34375 gr. | 1.7718454 grams (g. or gm,)| 1,771.8454 mg.
1 ounce (oz.) | 16 dr. 28.349527 g. (28,349,527 mg.
1 pound (1b.) | 16 oz. | 0.4535924277 kilogram (kg) 453.5924277 g.
1 short ton i 2000 lb. 0.90718486 metric ton 907.18486 kg.
1 long ton / 2240 lb. 1.01604704 metric tons | 1,016. 04704 kg.
.015432356 gr. . Tes 1000 ue.



15.432356 gr./1 g. 1000 mg.

39.27396 oz. jl kg. 1000 g.
0.9842064 {1 metric ton 1000 kg.

long ton





.204622341 ib.
G23 2
short tons

0
0.5643833 dr.
2
1







CAPACITY - LIQUID MEASURE

The units of liquid measure have the same names in both the United States
and the imperial systems. Inno case, however, are they equal. The
imperial gallon, quart, and pint are about 20 percent larger, whereas
the imperial fluid dram and fluid ounce are about 4 percent smaller than
the like-named United States units.

At 39.29 F.(4°C.), when it is at maximum density, a United States
gallon of puve water weighs 8.345 pounds, an imperial gallon 10.022
pounds. At 62°F. (16.67° C.) these weights are 8.337 and 10 pounds.
Twelve United States gallons (96 pints) of pure water weigh 100 pounds
(very nearly) and 6 pints weigh 100 ounces (very nearly) at room temper-
ature. The United States gallon is equal to 231 cubic inches and the
imperial gallon to 277.418 cubic inches. There are 7.4805 United States
gallons or 6.229 imperial gallons in 1 cubic foot. The United States
gallon is the old English wine gallon no longer used in the British Empire.

Formerly in Chemical and entomological literature the cubic
centimeter (cc.) was commonly used as a misnomer for milliliter (ml.).
Fortunately this is no longer such general practice. 1 milliliter = 1.000028
cubic centimeters; conversely, 1 cubic centimeter = 0.999972 milliliter.
These units are related in the same sense as 231 cubic inches =1 gallon.
Occasionally the kiloliter is called a stere, but this word properly
refers to the cubic meter.





Units of Capacity - Liquid Measure

United States

1 fluid dram (fl. dr.)

fluid ounce (fl. oz.)
gill

pint (pt.)

quart (qt.)

gallon (gal.)

= SS ee ee

G296075 f). dr.
96075 fl. oz.
.20094 gills
.20094 pt.
.20094 qt.
.20094 gal.

= — —

Dez tUole tant:
1.05671 qt.

264.178 gal.

1/1024 gal.

& fdr.
4 Tl. 02.
4 gills
2 pt.

4 qt.

1686-11; dr.

4.80376 fl. oz.
4.80376 gills
2.40188 pt.
4.80376 qt.

33.8147 fl. oz.

1,056.71 qt.



1.0408 fl. dr.

1.0408 fl. oz.

0.83268 gill
83268 pt.
83268 qt.
83268 gal.

0.28157 fl.oz.

6799 gt.

219,97554 gal.



.69661 milliliters

(m1.)
sO n2o til.
.118292 liter (1.)
Soe t le
946330 1:
oooon le

8.3264 fl.oz.
4.1634 fl.oz.
3.33072 gills
1.66536 pt.
3.93072 Gt.

ebib.Le am Ls
412 mil.
A206 1,
spoo245 1;
1.13649 1.
4.54596 1.

1/1280 gal.
8 fl. dr.

Dr tl..0Z.

4 gills

2 pt.

4 qt.

- lanl.
So.196 tlozeiiel dh
879.9 %qt. 1 kiloliter (kl.)

Metric

3,696.61 microliters

29,572.9 Al.

118.292 ml.
473,167 ml.
946.333 ml.
3,785.332 ml.

a755 Usp yaa

28,412.0 ml.

142.06 ml.

568.245 ml.
1,136.49 ml.
4,545.96 ml.

1000 4).
1000 ml.

1000 1,





[oe
Equivalents for Teaspoonful, Tablespoonful, and Cup

A measuring cup and measuring spoons, the latter obtainable in nests
of several sizes, are useful for making dilutions under practical con-
ditions where great accuracy is not required. The values given here are
also useful in transposing the precise measurements of the laboratory
into commonly understood units when recommending an insecticide to
dooryard gardeners,

In the absence of suitable scales for weighing, the use of these
volumetric units for measuring powdered insecticides is a common
practice. Tables of equivalents for such use have been published (2).
With the more recently developed wettable powders, however, weight-
volume equivalents of wide application cannot be calculated because of
differences in bulk volume and toxicant content of the numerous products.
The expression ''a pint is a pound" is exact for materials with a specific
gravity of 0.96 and approximately true for water or for other materials
with specific gravities near 1, but it is not true for powdered materials
in general. It is suggested that those who wish to use volumetric meas-
urements for powdered insecticidal material should determine the weight
of such quantities as a tablespoonful and a pint, and record these figures
on the packages at hand. Weight dilution directions can then be transposed
to these volumetric units and the equivalents given here employed.

3 teaspoonfuls = 1 tablespoonful 16 tablespoonfuls:

2 tablespoonfuls = 1 fluid ounce 2 gills
16 tablespoonful 1/2 pint = 1 cup
8 fluid ounces *}- ee 8 fluid ounces

237 milliliters

3 teaspoonfuls
1/2 fluid ounce = 1 pint

4 fluid drams mo ctablespooniut 16 nina ounces = 2 cups

15 milliliters 473 milliliters
CAPACITY - DRY MEASURE

In the United States separate systems of capacity units are used for
liquid and dry measure. In the dry-measure system, based on a modern
standard of the Queen Anne bushel of colonial times, the pint and quart
are about 16 percent larger than the units of the same name used in
liquid measure. The pint of this system was originally designed to hold
1 pound of grain, presumably wheat. This relationship is not exact under
present definitions. The United States bushel contains 2,150.42 cubic
inches or 1.244 cubic feet.

The imperial system uses the same pint and quart in both dry and
liquid measures. The imperial gallon may also be used, 8 gallons being
1 bushel. The pint and quart of the United States dry measure system



ae

are about 3 percent smaller than the imperial units of the same name.
The Winchester bushel, sometimes mentioned in publications from the
British Empire, has the same capacity as the United States bushel. The
imperial bushel contains 2,219 cubic inches or 1.2843 cubic feet.

In the metric system, capacity either liquid or dry, is measured by
the liter and related units.

Units of Capacity - Dry Measure




United States Imperial Metric






0.96895 pt. - | 0.550599 liter (1.) | 550.599 milli-
liters (ml.)
1 937. ptt boLeLioe Tl: 110)198an1,

8. 80958 1.

1 pint (pt.)




96895 qt.
.96895 pk.| 7.7516 qt.|0.880958deka-__ |
| liter (dkl.) |

.96895 bu 3.8758 pk.| .352383hecto- | 3,52383dkl.

|

1 quart(qt.) }2 pt.
1 peck(pk) {8 pt.



1 bushel(bu)}4 pk.




; liter (hl.)

i
HOS205 pt. | - 1 pt. | - 0.568245 I 568.245 ml.
1.03205 qt. |2.0641 pt. |1 qt. | 2 pt. 1.13649 1. 1136.49 ml.
1.03205 pk. |8.2564qt. |1pk. 8 qt. 0.9092 dkl. | 9.092 1.
1.03205bu. |4.1282pk. |1 bu. 4 pk. | 36368 hl. 3.6368 dkl.

i
1.908102 qt. | 1.8162 pt.|0.8799 qt. |1.7598 pt.j1 1. 1000 ml.
1.13513 pk. | 9.08102 qt.J1.0999 pk. |8.799 qt. |1 dkl. LOWE
2.8378 bu. |11.3513 pk. |2.74975 bu. 10,999 pk. |1 hl. 10 dkl.



LINEAR, SQUARE, AND CUBIC MEASURE

Except for small differences in standards, the units of linear measure
in the imperial system are the same as those used in the United States and
the same conversion values may be used. It follows that this is likewise
true for the units of area (Square measure) and the units of volume (cubic
measure).

Units of linear measure occasionally encountered are the surveyor's
(or Gunter's) link and chain. The link is equal to 7.92 inches, and 100
links, equal to 66 feet, make one chain, The engineer's chain is 100 feet
long, being divided into 1-foot links. The nautical or geographical mile
is equal to 1 minute of arc on a great circle of the earth and equals
6080.2 feet. A fathom used in nautical measurements is equal to 6 feet.

—————————














Ses

The acre, the basic unit of agricultural area measurements, con-
tains 160 square rods or 10 square surveyor's chains. A square meas-
uring 208.71 feet on each side is approximately 1 acre.

The relationship between the specific gravity of liquids or solids and
cubic measure is of interest. Specific gravity x 1000 equals the weight
in grams of 1 cubic decimeter or (very nearly) the weight in ounces of
1 cubic foot of the material. Since 1 cubic foot equals 7.4805 gallons
(7.5 in round numbers), the weight-volume relationships of liquid or
solid insecticidal materials can be calculated where their specific
gravities are known,

Units of Length

United States and imperial | Metric





















finch (in.) = 2.94 Centimeters (cm.) | 25-4 mm.
1 foot (ft.) LZ in 3.048 decimeters (dm.){ 30.48 cm.
Pyandityds)) Pt 3°it. 0.9144 meter (m.) 9.144 dm.
1 rod (rd.) i iel Ge Seit: .502921 dekameter 5.02921 m..
(dkm.)
1 mile neoezZo ft. 1.6093472 kilometers
(km.) 1,609. 3472 m.



















Of03937 “in. | = 1 millimeter (mm.) 1000 microns (4)

5590010, = em, 10 mm.

. 3280833 ft. | 3.937 in. 1 dinv. £O"'em:
Ussetth yd.) 39.37 in. ane 10 dm.
1.988384 rd. {10.936111 yd. 1 dkm. Oran

.6213699 mile 98.8384 rd. 1 km. 1000 m.



Units of Area

ann nnn nn nnn nnn nnn nena nnn cer rn SS SSS

United States and imperial Metric
ee SS SP ee ee eee
1 square inch(sq. in.) - | 6.451626 square centimeters(cm 2), 645.1626 square millimeters (mm.?)
1 square foot(sq. ft.) | 144 sq. in. | 9.290341 square decimeters(dm.2) | 929.0341 cm#
1 square yard(sq.yd.} 9 sq. ft. | 0.8361307 square meter (m.?) | 83,61307 dm2
1 square rod(sq.rd.) | 30.25 sq. yd. | .2529295 are | 25,.29295 m2
1 acre | 43,560 sq.ft. | . 404687 hectare (ha.) | 40.4687 ares
| eee eee eer
SS
0.15499969 sq. in. - | 1em2 | 100 mm 2
.1076387 sq. ft. 15.499969 sq.in.j 1 dm2 100 cm2
1.195985 sq. yd. 10.76387 sq.ft. | 1 m2 /100 dm2
3.95367 sq. rd. 119.5985 sq. yd. | 1 are | 100 m2
2.47104 acres 895.367 sq: irdij 4 1 ha. 100 ares



Units of Volume

LL

}



1000 dm3

United States and imperial Metric
1 cubic inch(cu. in.) | : ' 16,387162 cubic centimeters | 16,387,162 cubic millimeters
(cm3 OF ‘ec;) | (mm.3)
1 cubic foot(cu. ft.) 1,728 cu. in. | 28.317016 cubic decimeters(dm.3) 28,317.016 em3
1 cubic yard(cu. yd.) a0 Cu, tte | 0.7645594 cubic meter (m.3) | 764.5594 dm3
| t
0,06102338 cu.in, : | lem3 | 1000 mm3
.03531445 cu.ft. {| 61.02338 cu.in.}| 1 dm3 | 1000 em3

1.3079428 cu. yd, | 35.31445 cu.ft, | 1m3









=f

DILUTING INSECTICIDAL CHEMICALS
Equivalent Quantities for Various Quantities of Water

Powdered material. --The quantity of powdered insecticidal chemical
recommended for use in sprays is usually stated in pounds per 50 or 100
gallons of water. Quantities in smaller quantities of water giving the
same concentration as 1 to 5 pounds in 100 gallons are shown in table 1,

Note that the number of pounds per 100 gallons is the same as the
number of ounces per 61/4 gallons. This relationship is also true for
50 and 31/8 gallons.

Liquid material. --Similar equivalents for use with liquid insecticidal
materials, wetting agents, and the like are also shown in table 1. The
relationship of pounds and ounces noted for powdered material holds
here for pints and fluid ounces.

Concentration on the Basis of Percentage of Toxicant

In the preparation of sprays, dips, or dusts with certain insecticidal
chemicals, the concentration is often based on the percentage by weight
of the toxicant desired in the finished insecticide. The following equations
may be found useful in determining the correct quantity of insecticidal
chemical to use:

Suspensions, --To determine the quantity of insecticidal chemical
necessary for a given percentage of toxicant in the diluted spray, multiply
the number of gallons of spray to be made by 8.345 by the percent of
toxicant desired, and divide by the percent of toxicant in the powdered
material.

Example: 100 gallons of spray containing 0.06 percent of methoxy-
chlor is to be prepared from a wettable powder containing 50 percent of
the toxicant. The quantity of this powder to use is--

100 x 8.345 x 0.06

= 1 pound
50 '

To calculate the quantity of insecticidal chemical in grams, substi-
tute 3,700.3 for 62345,

The percentages of toxicant in 100 gallons of spray when 1 pound of
wettable powder is used, calculated for powders of eight toxicant levels,
are given in table 2. The quantities of these wettable powders necessary
to give three concentration levels in 100 gallons of spray have also been
calculated. These quantities may be rounded further, if necessary, in

field work,



= jo8

Table 1. --Quantities of insecticidal material giving the same concentra-
tion in various quantities of water

Water | Insecticidal material

Powder

100 gal. F ib, 2 |b. 3 Ib. 4 lb. J 1s

50 gal. 1/2 Tb. rtp; 1 1/2 lb. 2 lb. 2172 Vie

25 gal. 4 oz. 8 oz. 2 ext 1 Th. 1 1/4 lb.

t21j2 gal. 2 oz. 4 oz. 6 oz. 8 Oz. 10oz.
61/4 gal. 1 oz. 2 OZ. 3 OZ. 4 oz. Do OZ.
31/8 gal. 1/2 oz. 1 oz. 11/2 oz. 2 oz. 2 1/2 oz.
1 gal. 4.5 g. Sch ge: 13.6 g. 15.1 3. 22.0 Bs
1 qt. 1.134 g. 2.268 ¢. 3.402 ¢. 4.536 5.670 g.
ae 1.198 g. 2.397 g. 3.595g. 4.793 ¢. 5.991 g.

Liquid
100 gal. 1/2 pt. inpt: To: 2 Qt. 1 pat:

50 gal. 1/4 pt. 1/2 pt. 1 pt. 1 dic. it.

25 gal. 2 fl..o2, AT Om. 8 flioz. 1 pi 1 gt

W212 eal. 1 fl. oz, Pell Om: 4 fl.oz. 8 fl. oz. 1 pt.
6 1/4 eal.’ 1/2 fl oz. ith, Oz 2 th eee 4 fl.oz. ha a 9
31/8 gal. 1/4 fl.oz. V2 "ti-oz.* pines. 2 fl. OZ. 4 fl. oz.
1 gal. 2a Ia, 4.7 ml. 9-2 mls 18.9 1a: 31. om.
1 qt. 0.591 mil: 1.183 ml. 2.366 ml.: “4.732 mk” 32462
$e] 0.625 ml. 1.250 ml. 2.500 ml. 5,000 milly f0.000rae

ee







eA

Table 2. --Quantities of wettable powders of different strengths to give
sprays or dips containing three concentrations of the toxicant

Percent of | Pounds to make 100 gallons Percent of toxicant

toxicant in equivalent to 1 pound
wettable powder 9.25 percent} 0.5 percent] 1 percent per 100 gallons

20 1

|
OL 20.9 ie Atay 0.024
30 7.0 erage 9778 036
40 5.2 10.4 20.9 048
50 4.2 | 8.3 16.7 .06
60 3.5 7.0 are: O72
70 3.0 6.0 13 084
80 2.6 5.2 | 10.4 .096
90 2.3 4.6 9.3 108

Emulsions and solutions. Diluting by weight. --To determine the

quantity in gallons of an emulsion or solution concentrate to use in
making up a spray containing a given percentage of toxicant by weight,
multiply the number of gallons of spray to be made by the percentage of
toxicant desired, and divide by the percent of toxicant in the concentrate
times its specific gravity.

Example: 100 gallons of spray containing 2 percent of chlordane by
weight is to be prepared from a 40-percent emulsion concentrate having
a specific gravity of 1.02. The amount of the concentrate to use is-=

100 x2

ae A palions
40x 1.02

Sufficient water is added to make 100 gallons of spray.

For field application, dosages of insecticides are often given in pounds
of toxicant per acre. To determine the weight of toxicant, in pounds, in
1 gallon of emulsion concentrate, multiply 8.345 by the specific gravity
of the concentrate by the percent of toxicant in the concentrate and divide
by 100.

Example: An emulsion concentrate containing 45 percent of chler-
dane by weight and having a specific gravity of 1.07 is to be used. Each
gallon of the concentrate contains--~-

cei = 4 pounds of chlordane
100
The quantity of water to be added depends on the method of application.
If 1 pound of chlordane is required per acre, 1 quart of the above



= here

concentrate should be used in the quantity of spray that the apparatus at
hand will deliver per acre.

Specific gravity of a product is often unknown to the average user.
These formulas can be used, leaving this factor out, and the results will
be close enough for rough determinations.

Emulsions and solutions. Diluting by parts. --Emulsion and solution
concentrates may be diluted by parts to obtain a desired percentage of
toxicant in the finished spray or dip. It should be borne in mind, how-
ever, that 1 part of insecticidal chemical to so many parts of water is
not the same as in So many parts of finished spray. The difference is
of no great importance in the field use of dilute sprays, but it is of
significance in the formulation of concentrated sprays and, of course,
the distinction is desirable in the interest of precise terminology.

For diluting by parts divide the percent of toxicant in the concentrate
by the percent desired in the finished insecticide. The result is the
number of parts of the finished product that must contain 1 part of the
concentrate. The liquid-capacity measuring unit to be used will depend
on the total quantity of finished insecticide needed.

Example: A dip containing 0.2 percent of toxaphene is desired, and
the concentrate contains 60 percent of the toxicant.

60 + 0.2 = 300

The dilution is therefore 1 part of the concentrate in 300 parts of finished
insecticide or 1 part of the concentrate to 299 parts of water.

To determine the percentage of toxicant in a spray or dip made up on
the basis of parts, divide the percent of toxicant in the concentrate by
the number of parts of the spray.

Example: A spray was made by diluting an extract of pyrethrum
containing 2 percent of total pyrethrins at the rate of 1 part in 400 parts
of spray.

2 +400 = 0.005 percent of pyrethrins in the spray

Dusts. --To determine the weight of insecticidal material to use in
preparing a dust containing a given percentage of toxicant, multiply the
percentage of toxicant desired by the pounds of dust to be made and
divide by the percentage of toxicant in the insecticidal material to be
used,

Example: 100 pounds of dust containing 0.5 percent of rotenone is
to be prepared from powdered root containing 4 percent of rotenone.
The quantity of the root necessary is-=

0.5x100 = 12,5 pounds
4

Then add sufficient dilutent to make 100 pounds.





a

The percentage of toxicant in a dust may be determined when the
quantity of insecticidal chemical used and its percentage of toxicant, as
well as the total weight of the prepared dust, are known. Multiply the
number of pounds of insecticidal chemical used by its percentage of toxi-
cant, and divide by the number of pounds of dust prepared.

Example: 20 pounds of a powder containing 10 percent of DDT was
used in making up 100 pounds of dust. The DDT content of the dust was--

ee 2 percent
100

Concentration Expressed in Parts per Million

Very dilute concentrations are often expressed in parts per million
(p.p.m.) or as 1 part per stated number of millions, weight per weight
or volume per volume. A list of equivalents is tabulated below.

Parts i Part per Parts lt Part per
per indicated per indicated

million millions million millions

0.001 1000 0.05 20.0
.002 500 .08 12.5
.004 250 ai 10.0
.005 2006 2 2.0
.008 125 4 2.9
204 100 oO 2.0
02 50 a0 120
.04 25 i260 1.0

In United States units 1 ounce in 7,500 gallons (more nearly 7,489.51)
or 1 pound in 120,000 gallons (more nearly 119,832.22) is approximately
1 part per million by weight in water. One fluid ounce in 7,812.5 gallons
is 1 part per million by volume. In metric units 1 part per million may
be expressed as follows: By weight 1 milligram per kilogram, by volume
inmaicroliter per liter.

DOSAGE EQUIVALENTS AND RELATIONSHIPS
Dusts and Soil Insecticides

The quantities of dust or soil insecticide necessary for large-scale
application, in pounds per acre, may be calculated from the quantities
used in small-scale tests as follows: Multiply the number of grams or

ounces per square foot by 43,560, or per square yard by 4,840, and
divide by 453.59 if the dosage is in grams and by 16 if it is in ounces.



6

Example: A dust has been found effective in small-scale tests when
used at the rate of 0.3 gram per square foot. The equivalent dosage per

ld --
acre wou be 0.3x 43,560

453.59
To determine the number of square feet (or square yards) that 1 pound
of a given material will cover when the dosage per square foot (or square
yard) is known, divide 453.59 by this dosage if it is in grams, and 16 by
this dosage if it is in ounces.
Example: In the dosage of 0.3 gram per square foot mentioned above,
1 pound of the material would cover--~

453.59
0.3

To determine the quantity of material to be used for 1 square foot
when the large-scale dosage is known, multiply the number of pounds per
acre by 453.59 to obtain the number of grams, and by 16 to obtain the
number of ounces, and divide the product by 43,560. For dosages per
square yard divide by 4,840.

Examples: A dosage equivalent to 30 pounds per acre of a given dust
is to be tried on a small scale. The dosage per square foot is--

= 29 pounds

= 1,512 square feet

30x453.59 _ 3006.
mae) 0.31 gram Jer 43,560 ~ 0.011 ounce

Some values that have been worked out for convenient reference are
given in table 3,

Dosages in grams per square foot and pounds per acre are related
approximately as follows: Grams per square foot x 100 = pounds per acre.

Table 3. --Large-scale dosages equivalent to various
small-scale dosages



Dosage per Square feet that Pounds
square foot 1 pound will cover per acre
Gram
OL! 4,536 9.6
.10413 4,356 10.0
15619 2,904 15.0
.20 1,814 24.0
.26032 1,742 25.0
Ounce
0.005 3,200 13.61
.008 2,000 21.78
eOT 1,600 27.22
Org 1,000 43.56
.025 640 68.06
.064 250 174.24
.16 100 435.6

a ——————————————————————————————————————





: = ~5'=

It is frequently desirable to make such conversions on a weight~per-
volume basis. A recent paper by Floyd Smith (7) gives a table for
converting pounds per acre of soil 6 inches deep to equivalent dosages
for various volumes of soil in pots and other containers. His conversion
table is presented in table 4.

Table 4. --Milligrams equivalent to 1 pound per 6-inch acre
in various soil units












. Cubic centimeters Equivalent
Soil unit milligrams
of soil
per unit

Standard pots:

3-inch 180 O.la2Z
4-inch 500 .368
5-inch 900 .662
6-inch 1,500 Laie
7-inch 2,400 1.765
8-inch 3, 0o0 2.784
Short pot, 8-inch 2,900 yA Ws
Pan, 8-inch 1,400 1.030
Liter 1,000 730
Gallon 3,10 2.784
Cubic foot Zoro’ 20.826
Bushel SO,230 25.916





= th
Weight-Volume Relationships in Dosage Estimation

Surface application. --Dosage of residual insecticides for surface
application are often given in milligrams of toxicant per square foot.

If the percentage by weight of toxicant and the Specific gravity of the
spray are known, the approximate number of square feet that 1 gallon
will cover at a stated dosage can be estimated by use of table 5. Select
the factor opposite the dosage required and under the Specific gravity of
the spray at hand. Multiply this factor by the percentage of toxicant in
the spray. Water suspensions of wettable powder may be regarded as
having a specific gravity of 1.

Example: We wish to estimate the approximate number of square
feet that 1 gallon of 5-percent DDT solution will cover at a dosage of
150 milligrams per square foot. The specific gravity of the oil solution
is about 0.8. The factor 200 is read from table 5 and the calculation
made as follows: 200x5 = 1000 square feet.

Field application. --Dosage in milligrams per square foot is approxi-
mately one-tenth the dosage in pounds per acre. The dosage figures in
table 5 can therefore be read as pounds per acre by pointing off one
place. To estimate the gallonage of spray required to produce a stated
dosage in pounds of toxicant per acre, divide 45,300 by the selected
factor in table 5 times the percent of toxicant in the spray.

Example: A dosage of 2.5 pounds of DDT per acre is to be applied
by airplane. The oil solution to be used contains 10 percent of DDT and
has a specific gravity of 0.9.

45,300

is0na 3.33 gallons per acre

Table 5 --Factors for use in estimating surface coverage of
residual formulations and gallonage per acre




Specific gravity





Dosage,
imig.. per sq. ft.)

10 3000 3400 3800 4200
295 1200 1360 1520 1680
50 600 680 760 840
75 400 453 506 560
100 300 340 380 420
150 200 227 253 280
200 150 170 190 210











=. eve
Dosage Estimates for Row Crops
Equivalent dosages for certain acre rates and the areas or feet of
row of three different spacings that 1 gallon of spray or 1 pound of dust
will cover are given in table 6. Estimates of the requirements for areas

less than an acre can be made from these figures.

Table 6.--Dosages for row crops equivalent to various dosages per acre




1 Gallon or 1 pound will cover

Rate per acre Feet of row with spacing between rows of







Square feet




21/2 feet 3 1/2 feet



Sprays
Gallons
5 8,712 3,485 2,904 2,489
10 4,356 1,742 1,452 1,245
25 i742 697 581 498
50 871 348 290 249
75 581 232 194 266
100 436 [74 145 125
200 218 87 73 62
Dusts
Pounds
5 6.712 3,485 2.904-., 2,489
10 4,356 1742 1,452 1,245
15 2,904 1,162 968 830
20 2178 871 726 622
25 (eA: - 697 581 498
50 871 348 290 249

a ——————————————————————————

FUMIGATION

Dosages of fumigants are commonly given in ounces or pounds per
1000 cubic feet. Metric equivalents may be calculated on the basis of the

following relationship:
1 pound per 1000 cubic feet = 16.01894 milligrams per cubic decimeter
or
Milligrams per cubic decimeter
1.00118
Thus milligrams per cubic decimeter is approximately equal to ounces per
1000 cubic feet.

= ounces per 1000 cubic feet



T=

This relationship is of value in transposing laboratory dosages to
conventional units for large-scale work and in determining the concen-
tration of a fumigant, within a fumigation chamber, after proper chemical
analysis of aspirated quantitative samples.

Other conversion values for gas concentrations that may be of value
in fumigation studies are as follows:

1 cubic millimeter per cubic decimeter (liter) = 1 part per million
by volume

1 percent by volume = 10,000 parts per million

Low concentrations of fumigants or vapors in the air, where the
concentration in milligrams per cubic decimeter (liter) is determined,
sometimes are expressed directly as parts per million-#i.e., parts by
weight to a million parts by volume. Unless it is clearly explained,
such use of the expression "parts per million" is best avoided, that
statement being reserved for ratios of weight to weight or of volume to
volume.

The conversion of any weight-per-unit-volume ratio to a volume-
per-unit-volume ratio, such as parts of vaporized fumigant per million
parts of air, involves an understanding of the gram-molecular volume
relationship. This may be stated as follows: The volume of a gram-
molecule of a gas at 0OC. and 760 mm. of mercury is equal to 22.4
liters. At 25°C, and 760 mm. of mercury the volume is 24.45 liters
or 24,450 milliliters. The latter figures approximate the conditions
encountered in practical fumigation work. Conversion formulas based
on these figures are as follows:

24,450 xmilligrams per cubic decimeter

molecular weight = parts per million

Parts per = a molecular weight _ milligrams per cubic
’ decimeter

Example: A concentration of lindane vapor of 0.0006 milligram per
cubic decimeter has caused high mortality of house flies. The molecular
weight of this material is 290.85. The concentration may be expressed
in parts per million by volume as follows:

24450 x 0.0006

390.85 = 0.05 p.p.m., which is equivalent to 1 part in

20 miilion
Certain physical constants for a group of common fumigants are

presented in table 7. The figures for milliliters per pound and per
gallon have been rounded. Precise figures may be obtained by use of

the specific gravity.











ato..

Table 7, --Physical constants for several common fumigants





Pounds
per
gallon




Milliliters
per pound




Fumigant






Acrylonitrile 78 93.06 0.797 569 6.7
Carbon disulfide 46.3 76.13 1.263 359 10,5
Carbon tetrachloride 76.8 153.84 1.595 284 13,3
Chloropicrin £12 164,39 1.651 275 13.8
Dichloroethyl ether 178 143.02 1.222 onl 10.2
Ethylene dibromide 131.6 187.88 2.180 208 18.2
Ethylene dichloride 83.7 98.97 1.257 361 10.5
Ethylene oxide NOEs 44,05 0.887(109/49 511 fer
Hydrocyanic acid 26 27.03 0.688 659 9.7
Methyl bromide 4.6 94.95 1.732(00/40) 262 14,4
Trichloroethylene 87 131.40 1.477 307 12.3
MISCELLANEOUS

Capacity of Sprayer Tank

The capacity, in gallons, of the tanks on sprayers may be calculated
as follows:

Cylindrical tanks: Multiply length by square of the diameter, in
inches, by 0.0034.

Rectangular tank: Multiply length by width by depth, in inches, by
0.004329.

Tanks with elliptical cross section: Multiply length by short diameter
by long diameter, in inches, by 0.0034.

Diluting Miscible Liquids by Volume

Commercial grain alcohol of known percentage concentration can
be diluted as follows: Into a 100-ml. graduate pour as many milliliters
of the stronger solution as the percentage required in the weaker. Then
add water until the mixture reaches the milliliter mark equivalent to the
percentage of the stronger solution.

Example: To make 70-percent from 95-percent alcohol, pour into
the graduate 70 ml. of the 95-percent solution and fill to the 95-ml.
mark with water. The result is 95 ml. of a 70-percent solution.

The same procedure can be used for any other liquid, such as
acetone, that is miscible with water, and in fact for any pair of miscible

liquids.



-20-

Temperature Conversion

The two most commonly used thermometric systems are Centigrade
(C.) and Fahrenheit (F.). Equivalentsfor the two scales may be calculated
as follows:

CC. = (2 se) et saan
ORt He. eels

A number of equivalents for the two scales are presented below:







Oy, ** ee. Ve Ort OC; : Ol «, eles
pare 4 80 26.67 | 158 70
10.” <12-29) bi 86 30 TO, * “oer
14 -10 90 52.227 170° "76367
20 = - 6.67 100 ae 176 80
200 Sebi l 34 104 40 | 180 82.22
32 0 i 110 43233 190 gees
40 4.44 | 120 48.89 194 90
50 10 122 50 200 93.33
60 15-56 130 54,44 | 210 98.89
68 20 | 140 60 | 212 100
70 Zt 150 65.56

LITERATURE CITED

(1) Bearce, Henry W.
1936. United States and British units of weights and measures.
Sci. Monthly 43: 566-568.

(2) Howard, N. F., Weigel, C. A., Smith, C..M., and Stemer> 208.
1945. Insecticides and equipment for controlling insects on
fruits and vegetables. Rev. U.S. Dept. Agr. Misc.
Pub,..526;7 b6-pp.

(3) Irwin, K. G.
1951. Fathoms and feet, acres and tons: Anappraisal. Sci.
Monthly 72(1): 9-17.

(4) National Bureau of Standards
1936. Units of weight and measure (United States customary
and metric). Definitions and tables of equivalents,
/U.S./ National Bur. Standards, Misc. Pub. M 121,

68 pp.





= he

(5) National Bureau of Standards
1920. Household weights and measures. U. S. Bur. Standards,
Misc. Pub. 39, 2 pp.

(6) National Research Council
1926. International critical tables of numerical data, physics,
chemistry and technology. v. 1, pp. 1-15. New York.

(7) Smith, Floyd F.
1952. Conversion of per-acre dosages of soil insecticide to
equivalents for small units. Jour. Econ. Ent. 45:
339-340.

$$$







UNIVERSITY OF FLORIDA

MONA A

62 09224 7575





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FILES




LIBRARY
TATE PLARY PA3ARD E-517, revised

United States Department of Agriculture
Agricultural Research Administration
Bureau of Entomology and Plant Quarantine

CONVERSION TABLES AND EQUIVALENTS FOR USE
IN WORK RELATING TO INSECT CONTROL

By R. H. Nelson
Division of Stored Product Insect Investigations



Contents
Page
IAS St cui RM ee ey okie G's, 0, 0, fn nia bag eine 2
Capacity - liquid - measure. REMY ies). oy, 0, iota yay oes 3
Equivalents for teaspoonful, tablespoonful, and cup. 5
Capacity - dry measure. : 5
MiG Wemagiire amd CUDLC IMECAaSUTE . . 24 6 6 5 s+ eis es ow ww 6
Primm antsecticidal Chemicals ..... ++ ss : 9
Equivalent quantities for various Ge ateres of ater 2 oat 9
aa Concentration on the basis of percentage of toxicant 9
Concentration expressed in parts per million. Le
Dosage equivalents and relationships . 13
Dusts.and soil insecticides ; 13
Weight-volume relationships in ee seiner oes ni 16
eee mnt ates 1Oi KOW CrODS 0... 42, «2. %. +) +) s 0-0 ee yz
Pier OMO NG ee bs eile a ie ee es awe 17
Miscellaneous 6 Ae 19
Capacity of eee cae Se, ake eee ie
Peano etaiscinie liqgids by volume .. .. .. +. + ++ +6 19
WeeaarertateIGe PC OMVEL SION 05 66 2 an se ) se ee wk te ew we tee 60
Sb dil acetal

mnie OU es a ee os sks esas ye ss oele 0 @ 0 6.8
AD

In the literature on economic entomology the weights and measures
used in expressing concentrations and dosages of insecticides may be in
one or more of three systems--the United States, the imperial (British),
and the metric. Since information on the relationships and equivalents
in these systems is not always readily available to entomologists in the
field, it has been assembled here for their benefit. The data on equiva-
lents are taken principally from publications of the National Bureau of
Standards (4, 5) and the International Critical Tables (6). A comparative
discussion of United States and British units by Bearce (1) and a paper
by Irwin (3) were sources of valuable information. ai

Tables of equivalents for use in diluting insecticides, methods of
calculating concentrations on the basis of active ingredients, and certain
other miscellaneous information useful to entomologists working with
insecticides have also been included.

The measurement equivalents are carried out to sufficient decimal
places to furnish accurate figures for precise laboratory work. They
can be rounded out at the decimal place best suited for the equipment
of the individual worker. The concentration equivalents have been
carried out one to three places. In recommendations for practical use
it is suggested that values be given as whole numbers or in steps of
one-half wherever possible without gross error.

MASS

The basic units of the United States and British imperial avoirdupois
systems differ in definition, but are equal for practical purposes. There
are certain differences in terminology between the two systems that
should be noted. A stone of the imperial system is 14 pounds. That
system also uses 112 pounds as a hundred weight and 2,240 pounds as a
ton. The hundredweight of the United States system is 100 pounds and
2,240 pounds is called a long ton. The latter unit is also the gross ton
of maritime commerce, being criginally based on an estimate of 12
pounds of container per 100 pounds of commodity.

The apothecaries and troy weight systems should not be used in
entomological work, and fortunately their use elsewhere is dwindling.
Except for the grain,yhomonymous units in these systems and the avoir-
dupois system are not equal.

The metric ton is sometimes referred to as a millier or a tonneau,


~

Units of Mass



Metric





U.S. andimperial avoirdupois

|
igerain(gr.) 1 1/7000 Ib. 64.798918 milligrams(mg,) |64,698.918 micrograms



! (Aug. ory
1 dram (dr.) {| 27.34375 gr. | 1.7718454 grams (g. or gm,)| 1,771.8454 mg.
1 ounce (oz.) | 16 dr. 28.349527 g. (28,349,527 mg.
1 pound (1b.) | 16 oz. | 0.4535924277 kilogram (kg) 453.5924277 g.
1 short ton i 2000 lb. 0.90718486 metric ton 907.18486 kg.
1 long ton / 2240 lb. 1.01604704 metric tons | 1,016. 04704 kg.
.015432356 gr. . Tes 1000 ue.



15.432356 gr./1 g. 1000 mg.

39.27396 oz. jl kg. 1000 g.
0.9842064 {1 metric ton 1000 kg.

long ton





.204622341 ib.
G23 2
short tons

0
0.5643833 dr.
2
1







CAPACITY - LIQUID MEASURE

The units of liquid measure have the same names in both the United States
and the imperial systems. Inno case, however, are they equal. The
imperial gallon, quart, and pint are about 20 percent larger, whereas
the imperial fluid dram and fluid ounce are about 4 percent smaller than
the like-named United States units.

At 39.29 F.(4°C.), when it is at maximum density, a United States
gallon of puve water weighs 8.345 pounds, an imperial gallon 10.022
pounds. At 62°F. (16.67° C.) these weights are 8.337 and 10 pounds.
Twelve United States gallons (96 pints) of pure water weigh 100 pounds
(very nearly) and 6 pints weigh 100 ounces (very nearly) at room temper-
ature. The United States gallon is equal to 231 cubic inches and the
imperial gallon to 277.418 cubic inches. There are 7.4805 United States
gallons or 6.229 imperial gallons in 1 cubic foot. The United States
gallon is the old English wine gallon no longer used in the British Empire.

Formerly in Chemical and entomological literature the cubic
centimeter (cc.) was commonly used as a misnomer for milliliter (ml.).
Fortunately this is no longer such general practice. 1 milliliter = 1.000028
cubic centimeters; conversely, 1 cubic centimeter = 0.999972 milliliter.
These units are related in the same sense as 231 cubic inches =1 gallon.
Occasionally the kiloliter is called a stere, but this word properly
refers to the cubic meter.


Units of Capacity - Liquid Measure

United States

1 fluid dram (fl. dr.)

fluid ounce (fl. oz.)
gill

pint (pt.)

quart (qt.)

gallon (gal.)

= SS ee ee

G296075 f). dr.
96075 fl. oz.
.20094 gills
.20094 pt.
.20094 qt.
.20094 gal.

= — —

Dez tUole tant:
1.05671 qt.

264.178 gal.

1/1024 gal.

& fdr.
4 Tl. 02.
4 gills
2 pt.

4 qt.

1686-11; dr.

4.80376 fl. oz.
4.80376 gills
2.40188 pt.
4.80376 qt.

33.8147 fl. oz.

1,056.71 qt.



1.0408 fl. dr.

1.0408 fl. oz.

0.83268 gill
83268 pt.
83268 qt.
83268 gal.

0.28157 fl.oz.

6799 gt.

219,97554 gal.



.69661 milliliters

(m1.)
sO n2o til.
.118292 liter (1.)
Soe t le
946330 1:
oooon le

8.3264 fl.oz.
4.1634 fl.oz.
3.33072 gills
1.66536 pt.
3.93072 Gt.

ebib.Le am Ls
412 mil.
A206 1,
spoo245 1;
1.13649 1.
4.54596 1.

1/1280 gal.
8 fl. dr.

Dr tl..0Z.

4 gills

2 pt.

4 qt.

- lanl.
So.196 tlozeiiel dh
879.9 %qt. 1 kiloliter (kl.)

Metric

3,696.61 microliters

29,572.9 Al.

118.292 ml.
473,167 ml.
946.333 ml.
3,785.332 ml.

a755 Usp yaa

28,412.0 ml.

142.06 ml.

568.245 ml.
1,136.49 ml.
4,545.96 ml.

1000 4).
1000 ml.

1000 1,


[oe
Equivalents for Teaspoonful, Tablespoonful, and Cup

A measuring cup and measuring spoons, the latter obtainable in nests
of several sizes, are useful for making dilutions under practical con-
ditions where great accuracy is not required. The values given here are
also useful in transposing the precise measurements of the laboratory
into commonly understood units when recommending an insecticide to
dooryard gardeners,

In the absence of suitable scales for weighing, the use of these
volumetric units for measuring powdered insecticides is a common
practice. Tables of equivalents for such use have been published (2).
With the more recently developed wettable powders, however, weight-
volume equivalents of wide application cannot be calculated because of
differences in bulk volume and toxicant content of the numerous products.
The expression ''a pint is a pound" is exact for materials with a specific
gravity of 0.96 and approximately true for water or for other materials
with specific gravities near 1, but it is not true for powdered materials
in general. It is suggested that those who wish to use volumetric meas-
urements for powdered insecticidal material should determine the weight
of such quantities as a tablespoonful and a pint, and record these figures
on the packages at hand. Weight dilution directions can then be transposed
to these volumetric units and the equivalents given here employed.

3 teaspoonfuls = 1 tablespoonful 16 tablespoonfuls:

2 tablespoonfuls = 1 fluid ounce 2 gills
16 tablespoonful 1/2 pint = 1 cup
8 fluid ounces *}- ee 8 fluid ounces

237 milliliters

3 teaspoonfuls
1/2 fluid ounce = 1 pint

4 fluid drams mo ctablespooniut 16 nina ounces = 2 cups

15 milliliters 473 milliliters
CAPACITY - DRY MEASURE

In the United States separate systems of capacity units are used for
liquid and dry measure. In the dry-measure system, based on a modern
standard of the Queen Anne bushel of colonial times, the pint and quart
are about 16 percent larger than the units of the same name used in
liquid measure. The pint of this system was originally designed to hold
1 pound of grain, presumably wheat. This relationship is not exact under
present definitions. The United States bushel contains 2,150.42 cubic
inches or 1.244 cubic feet.

The imperial system uses the same pint and quart in both dry and
liquid measures. The imperial gallon may also be used, 8 gallons being
1 bushel. The pint and quart of the United States dry measure system
ae

are about 3 percent smaller than the imperial units of the same name.
The Winchester bushel, sometimes mentioned in publications from the
British Empire, has the same capacity as the United States bushel. The
imperial bushel contains 2,219 cubic inches or 1.2843 cubic feet.

In the metric system, capacity either liquid or dry, is measured by
the liter and related units.

Units of Capacity - Dry Measure




United States Imperial Metric






0.96895 pt. - | 0.550599 liter (1.) | 550.599 milli-
liters (ml.)
1 937. ptt boLeLioe Tl: 110)198an1,

8. 80958 1.

1 pint (pt.)




96895 qt.
.96895 pk.| 7.7516 qt.|0.880958deka-__ |
| liter (dkl.) |

.96895 bu 3.8758 pk.| .352383hecto- | 3,52383dkl.

|

1 quart(qt.) }2 pt.
1 peck(pk) {8 pt.



1 bushel(bu)}4 pk.




; liter (hl.)

i
HOS205 pt. | - 1 pt. | - 0.568245 I 568.245 ml.
1.03205 qt. |2.0641 pt. |1 qt. | 2 pt. 1.13649 1. 1136.49 ml.
1.03205 pk. |8.2564qt. |1pk. 8 qt. 0.9092 dkl. | 9.092 1.
1.03205bu. |4.1282pk. |1 bu. 4 pk. | 36368 hl. 3.6368 dkl.

i
1.908102 qt. | 1.8162 pt.|0.8799 qt. |1.7598 pt.j1 1. 1000 ml.
1.13513 pk. | 9.08102 qt.J1.0999 pk. |8.799 qt. |1 dkl. LOWE
2.8378 bu. |11.3513 pk. |2.74975 bu. 10,999 pk. |1 hl. 10 dkl.



LINEAR, SQUARE, AND CUBIC MEASURE

Except for small differences in standards, the units of linear measure
in the imperial system are the same as those used in the United States and
the same conversion values may be used. It follows that this is likewise
true for the units of area (Square measure) and the units of volume (cubic
measure).

Units of linear measure occasionally encountered are the surveyor's
(or Gunter's) link and chain. The link is equal to 7.92 inches, and 100
links, equal to 66 feet, make one chain, The engineer's chain is 100 feet
long, being divided into 1-foot links. The nautical or geographical mile
is equal to 1 minute of arc on a great circle of the earth and equals
6080.2 feet. A fathom used in nautical measurements is equal to 6 feet.

—————————











Ses

The acre, the basic unit of agricultural area measurements, con-
tains 160 square rods or 10 square surveyor's chains. A square meas-
uring 208.71 feet on each side is approximately 1 acre.

The relationship between the specific gravity of liquids or solids and
cubic measure is of interest. Specific gravity x 1000 equals the weight
in grams of 1 cubic decimeter or (very nearly) the weight in ounces of
1 cubic foot of the material. Since 1 cubic foot equals 7.4805 gallons
(7.5 in round numbers), the weight-volume relationships of liquid or
solid insecticidal materials can be calculated where their specific
gravities are known,

Units of Length

United States and imperial | Metric





















finch (in.) = 2.94 Centimeters (cm.) | 25-4 mm.
1 foot (ft.) LZ in 3.048 decimeters (dm.){ 30.48 cm.
Pyandityds)) Pt 3°it. 0.9144 meter (m.) 9.144 dm.
1 rod (rd.) i iel Ge Seit: .502921 dekameter 5.02921 m..
(dkm.)
1 mile neoezZo ft. 1.6093472 kilometers
(km.) 1,609. 3472 m.



















Of03937 “in. | = 1 millimeter (mm.) 1000 microns (4)

5590010, = em, 10 mm.

. 3280833 ft. | 3.937 in. 1 dinv. £O"'em:
Ussetth yd.) 39.37 in. ane 10 dm.
1.988384 rd. {10.936111 yd. 1 dkm. Oran

.6213699 mile 98.8384 rd. 1 km. 1000 m.
Units of Area

ann nnn nn nnn nnn nnn nena nnn cer rn SS SSS

United States and imperial Metric
ee SS SP ee ee eee
1 square inch(sq. in.) - | 6.451626 square centimeters(cm 2), 645.1626 square millimeters (mm.?)
1 square foot(sq. ft.) | 144 sq. in. | 9.290341 square decimeters(dm.2) | 929.0341 cm#
1 square yard(sq.yd.} 9 sq. ft. | 0.8361307 square meter (m.?) | 83,61307 dm2
1 square rod(sq.rd.) | 30.25 sq. yd. | .2529295 are | 25,.29295 m2
1 acre | 43,560 sq.ft. | . 404687 hectare (ha.) | 40.4687 ares
| eee eee eer
SS
0.15499969 sq. in. - | 1em2 | 100 mm 2
.1076387 sq. ft. 15.499969 sq.in.j 1 dm2 100 cm2
1.195985 sq. yd. 10.76387 sq.ft. | 1 m2 /100 dm2
3.95367 sq. rd. 119.5985 sq. yd. | 1 are | 100 m2
2.47104 acres 895.367 sq: irdij 4 1 ha. 100 ares



Units of Volume

LL

}



1000 dm3

United States and imperial Metric
1 cubic inch(cu. in.) | : ' 16,387162 cubic centimeters | 16,387,162 cubic millimeters
(cm3 OF ‘ec;) | (mm.3)
1 cubic foot(cu. ft.) 1,728 cu. in. | 28.317016 cubic decimeters(dm.3) 28,317.016 em3
1 cubic yard(cu. yd.) a0 Cu, tte | 0.7645594 cubic meter (m.3) | 764.5594 dm3
| t
0,06102338 cu.in, : | lem3 | 1000 mm3
.03531445 cu.ft. {| 61.02338 cu.in.}| 1 dm3 | 1000 em3

1.3079428 cu. yd, | 35.31445 cu.ft, | 1m3






=f

DILUTING INSECTICIDAL CHEMICALS
Equivalent Quantities for Various Quantities of Water

Powdered material. --The quantity of powdered insecticidal chemical
recommended for use in sprays is usually stated in pounds per 50 or 100
gallons of water. Quantities in smaller quantities of water giving the
same concentration as 1 to 5 pounds in 100 gallons are shown in table 1,

Note that the number of pounds per 100 gallons is the same as the
number of ounces per 61/4 gallons. This relationship is also true for
50 and 31/8 gallons.

Liquid material. --Similar equivalents for use with liquid insecticidal
materials, wetting agents, and the like are also shown in table 1. The
relationship of pounds and ounces noted for powdered material holds
here for pints and fluid ounces.

Concentration on the Basis of Percentage of Toxicant

In the preparation of sprays, dips, or dusts with certain insecticidal
chemicals, the concentration is often based on the percentage by weight
of the toxicant desired in the finished insecticide. The following equations
may be found useful in determining the correct quantity of insecticidal
chemical to use:

Suspensions, --To determine the quantity of insecticidal chemical
necessary for a given percentage of toxicant in the diluted spray, multiply
the number of gallons of spray to be made by 8.345 by the percent of
toxicant desired, and divide by the percent of toxicant in the powdered
material.

Example: 100 gallons of spray containing 0.06 percent of methoxy-
chlor is to be prepared from a wettable powder containing 50 percent of
the toxicant. The quantity of this powder to use is--

100 x 8.345 x 0.06

= 1 pound
50 '

To calculate the quantity of insecticidal chemical in grams, substi-
tute 3,700.3 for 62345,

The percentages of toxicant in 100 gallons of spray when 1 pound of
wettable powder is used, calculated for powders of eight toxicant levels,
are given in table 2. The quantities of these wettable powders necessary
to give three concentration levels in 100 gallons of spray have also been
calculated. These quantities may be rounded further, if necessary, in

field work,
= jo8

Table 1. --Quantities of insecticidal material giving the same concentra-
tion in various quantities of water

Water | Insecticidal material

Powder

100 gal. F ib, 2 |b. 3 Ib. 4 lb. J 1s

50 gal. 1/2 Tb. rtp; 1 1/2 lb. 2 lb. 2172 Vie

25 gal. 4 oz. 8 oz. 2 ext 1 Th. 1 1/4 lb.

t21j2 gal. 2 oz. 4 oz. 6 oz. 8 Oz. 10oz.
61/4 gal. 1 oz. 2 OZ. 3 OZ. 4 oz. Do OZ.
31/8 gal. 1/2 oz. 1 oz. 11/2 oz. 2 oz. 2 1/2 oz.
1 gal. 4.5 g. Sch ge: 13.6 g. 15.1 3. 22.0 Bs
1 qt. 1.134 g. 2.268 ¢. 3.402 ¢. 4.536 5.670 g.
ae 1.198 g. 2.397 g. 3.595g. 4.793 ¢. 5.991 g.

Liquid
100 gal. 1/2 pt. inpt: To: 2 Qt. 1 pat:

50 gal. 1/4 pt. 1/2 pt. 1 pt. 1 dic. it.

25 gal. 2 fl..o2, AT Om. 8 flioz. 1 pi 1 gt

W212 eal. 1 fl. oz, Pell Om: 4 fl.oz. 8 fl. oz. 1 pt.
6 1/4 eal.’ 1/2 fl oz. ith, Oz 2 th eee 4 fl.oz. ha a 9
31/8 gal. 1/4 fl.oz. V2 "ti-oz.* pines. 2 fl. OZ. 4 fl. oz.
1 gal. 2a Ia, 4.7 ml. 9-2 mls 18.9 1a: 31. om.
1 qt. 0.591 mil: 1.183 ml. 2.366 ml.: “4.732 mk” 32462
$e] 0.625 ml. 1.250 ml. 2.500 ml. 5,000 milly f0.000rae

ee




eA

Table 2. --Quantities of wettable powders of different strengths to give
sprays or dips containing three concentrations of the toxicant

Percent of | Pounds to make 100 gallons Percent of toxicant

toxicant in equivalent to 1 pound
wettable powder 9.25 percent} 0.5 percent] 1 percent per 100 gallons

20 1

|
OL 20.9 ie Atay 0.024
30 7.0 erage 9778 036
40 5.2 10.4 20.9 048
50 4.2 | 8.3 16.7 .06
60 3.5 7.0 are: O72
70 3.0 6.0 13 084
80 2.6 5.2 | 10.4 .096
90 2.3 4.6 9.3 108

Emulsions and solutions. Diluting by weight. --To determine the

quantity in gallons of an emulsion or solution concentrate to use in
making up a spray containing a given percentage of toxicant by weight,
multiply the number of gallons of spray to be made by the percentage of
toxicant desired, and divide by the percent of toxicant in the concentrate
times its specific gravity.

Example: 100 gallons of spray containing 2 percent of chlordane by
weight is to be prepared from a 40-percent emulsion concentrate having
a specific gravity of 1.02. The amount of the concentrate to use is-=

100 x2

ae A palions
40x 1.02

Sufficient water is added to make 100 gallons of spray.

For field application, dosages of insecticides are often given in pounds
of toxicant per acre. To determine the weight of toxicant, in pounds, in
1 gallon of emulsion concentrate, multiply 8.345 by the specific gravity
of the concentrate by the percent of toxicant in the concentrate and divide
by 100.

Example: An emulsion concentrate containing 45 percent of chler-
dane by weight and having a specific gravity of 1.07 is to be used. Each
gallon of the concentrate contains--~-

cei = 4 pounds of chlordane
100
The quantity of water to be added depends on the method of application.
If 1 pound of chlordane is required per acre, 1 quart of the above
= here

concentrate should be used in the quantity of spray that the apparatus at
hand will deliver per acre.

Specific gravity of a product is often unknown to the average user.
These formulas can be used, leaving this factor out, and the results will
be close enough for rough determinations.

Emulsions and solutions. Diluting by parts. --Emulsion and solution
concentrates may be diluted by parts to obtain a desired percentage of
toxicant in the finished spray or dip. It should be borne in mind, how-
ever, that 1 part of insecticidal chemical to so many parts of water is
not the same as in So many parts of finished spray. The difference is
of no great importance in the field use of dilute sprays, but it is of
significance in the formulation of concentrated sprays and, of course,
the distinction is desirable in the interest of precise terminology.

For diluting by parts divide the percent of toxicant in the concentrate
by the percent desired in the finished insecticide. The result is the
number of parts of the finished product that must contain 1 part of the
concentrate. The liquid-capacity measuring unit to be used will depend
on the total quantity of finished insecticide needed.

Example: A dip containing 0.2 percent of toxaphene is desired, and
the concentrate contains 60 percent of the toxicant.

60 + 0.2 = 300

The dilution is therefore 1 part of the concentrate in 300 parts of finished
insecticide or 1 part of the concentrate to 299 parts of water.

To determine the percentage of toxicant in a spray or dip made up on
the basis of parts, divide the percent of toxicant in the concentrate by
the number of parts of the spray.

Example: A spray was made by diluting an extract of pyrethrum
containing 2 percent of total pyrethrins at the rate of 1 part in 400 parts
of spray.

2 +400 = 0.005 percent of pyrethrins in the spray

Dusts. --To determine the weight of insecticidal material to use in
preparing a dust containing a given percentage of toxicant, multiply the
percentage of toxicant desired by the pounds of dust to be made and
divide by the percentage of toxicant in the insecticidal material to be
used,

Example: 100 pounds of dust containing 0.5 percent of rotenone is
to be prepared from powdered root containing 4 percent of rotenone.
The quantity of the root necessary is-=

0.5x100 = 12,5 pounds
4

Then add sufficient dilutent to make 100 pounds.


a

The percentage of toxicant in a dust may be determined when the
quantity of insecticidal chemical used and its percentage of toxicant, as
well as the total weight of the prepared dust, are known. Multiply the
number of pounds of insecticidal chemical used by its percentage of toxi-
cant, and divide by the number of pounds of dust prepared.

Example: 20 pounds of a powder containing 10 percent of DDT was
used in making up 100 pounds of dust. The DDT content of the dust was--

ee 2 percent
100

Concentration Expressed in Parts per Million

Very dilute concentrations are often expressed in parts per million
(p.p.m.) or as 1 part per stated number of millions, weight per weight
or volume per volume. A list of equivalents is tabulated below.

Parts i Part per Parts lt Part per
per indicated per indicated

million millions million millions

0.001 1000 0.05 20.0
.002 500 .08 12.5
.004 250 ai 10.0
.005 2006 2 2.0
.008 125 4 2.9
204 100 oO 2.0
02 50 a0 120
.04 25 i260 1.0

In United States units 1 ounce in 7,500 gallons (more nearly 7,489.51)
or 1 pound in 120,000 gallons (more nearly 119,832.22) is approximately
1 part per million by weight in water. One fluid ounce in 7,812.5 gallons
is 1 part per million by volume. In metric units 1 part per million may
be expressed as follows: By weight 1 milligram per kilogram, by volume
inmaicroliter per liter.

DOSAGE EQUIVALENTS AND RELATIONSHIPS
Dusts and Soil Insecticides

The quantities of dust or soil insecticide necessary for large-scale
application, in pounds per acre, may be calculated from the quantities
used in small-scale tests as follows: Multiply the number of grams or

ounces per square foot by 43,560, or per square yard by 4,840, and
divide by 453.59 if the dosage is in grams and by 16 if it is in ounces.
6

Example: A dust has been found effective in small-scale tests when
used at the rate of 0.3 gram per square foot. The equivalent dosage per

ld --
acre wou be 0.3x 43,560

453.59
To determine the number of square feet (or square yards) that 1 pound
of a given material will cover when the dosage per square foot (or square
yard) is known, divide 453.59 by this dosage if it is in grams, and 16 by
this dosage if it is in ounces.
Example: In the dosage of 0.3 gram per square foot mentioned above,
1 pound of the material would cover--~

453.59
0.3

To determine the quantity of material to be used for 1 square foot
when the large-scale dosage is known, multiply the number of pounds per
acre by 453.59 to obtain the number of grams, and by 16 to obtain the
number of ounces, and divide the product by 43,560. For dosages per
square yard divide by 4,840.

Examples: A dosage equivalent to 30 pounds per acre of a given dust
is to be tried on a small scale. The dosage per square foot is--

= 29 pounds

= 1,512 square feet

30x453.59 _ 3006.
mae) 0.31 gram Jer 43,560 ~ 0.011 ounce

Some values that have been worked out for convenient reference are
given in table 3,

Dosages in grams per square foot and pounds per acre are related
approximately as follows: Grams per square foot x 100 = pounds per acre.

Table 3. --Large-scale dosages equivalent to various
small-scale dosages



Dosage per Square feet that Pounds
square foot 1 pound will cover per acre
Gram
OL! 4,536 9.6
.10413 4,356 10.0
15619 2,904 15.0
.20 1,814 24.0
.26032 1,742 25.0
Ounce
0.005 3,200 13.61
.008 2,000 21.78
eOT 1,600 27.22
Org 1,000 43.56
.025 640 68.06
.064 250 174.24
.16 100 435.6

a ——————————————————————————————————————


: = ~5'=

It is frequently desirable to make such conversions on a weight~per-
volume basis. A recent paper by Floyd Smith (7) gives a table for
converting pounds per acre of soil 6 inches deep to equivalent dosages
for various volumes of soil in pots and other containers. His conversion
table is presented in table 4.

Table 4. --Milligrams equivalent to 1 pound per 6-inch acre
in various soil units












. Cubic centimeters Equivalent
Soil unit milligrams
of soil
per unit

Standard pots:

3-inch 180 O.la2Z
4-inch 500 .368
5-inch 900 .662
6-inch 1,500 Laie
7-inch 2,400 1.765
8-inch 3, 0o0 2.784
Short pot, 8-inch 2,900 yA Ws
Pan, 8-inch 1,400 1.030
Liter 1,000 730
Gallon 3,10 2.784
Cubic foot Zoro’ 20.826
Bushel SO,230 25.916


= th
Weight-Volume Relationships in Dosage Estimation

Surface application. --Dosage of residual insecticides for surface
application are often given in milligrams of toxicant per square foot.

If the percentage by weight of toxicant and the Specific gravity of the
spray are known, the approximate number of square feet that 1 gallon
will cover at a stated dosage can be estimated by use of table 5. Select
the factor opposite the dosage required and under the Specific gravity of
the spray at hand. Multiply this factor by the percentage of toxicant in
the spray. Water suspensions of wettable powder may be regarded as
having a specific gravity of 1.

Example: We wish to estimate the approximate number of square
feet that 1 gallon of 5-percent DDT solution will cover at a dosage of
150 milligrams per square foot. The specific gravity of the oil solution
is about 0.8. The factor 200 is read from table 5 and the calculation
made as follows: 200x5 = 1000 square feet.

Field application. --Dosage in milligrams per square foot is approxi-
mately one-tenth the dosage in pounds per acre. The dosage figures in
table 5 can therefore be read as pounds per acre by pointing off one
place. To estimate the gallonage of spray required to produce a stated
dosage in pounds of toxicant per acre, divide 45,300 by the selected
factor in table 5 times the percent of toxicant in the spray.

Example: A dosage of 2.5 pounds of DDT per acre is to be applied
by airplane. The oil solution to be used contains 10 percent of DDT and
has a specific gravity of 0.9.

45,300

is0na 3.33 gallons per acre

Table 5 --Factors for use in estimating surface coverage of
residual formulations and gallonage per acre




Specific gravity





Dosage,
imig.. per sq. ft.)

10 3000 3400 3800 4200
295 1200 1360 1520 1680
50 600 680 760 840
75 400 453 506 560
100 300 340 380 420
150 200 227 253 280
200 150 170 190 210








=. eve
Dosage Estimates for Row Crops
Equivalent dosages for certain acre rates and the areas or feet of
row of three different spacings that 1 gallon of spray or 1 pound of dust
will cover are given in table 6. Estimates of the requirements for areas

less than an acre can be made from these figures.

Table 6.--Dosages for row crops equivalent to various dosages per acre




1 Gallon or 1 pound will cover

Rate per acre Feet of row with spacing between rows of







Square feet




21/2 feet 3 1/2 feet



Sprays
Gallons
5 8,712 3,485 2,904 2,489
10 4,356 1,742 1,452 1,245
25 i742 697 581 498
50 871 348 290 249
75 581 232 194 266
100 436 [74 145 125
200 218 87 73 62
Dusts
Pounds
5 6.712 3,485 2.904-., 2,489
10 4,356 1742 1,452 1,245
15 2,904 1,162 968 830
20 2178 871 726 622
25 (eA: - 697 581 498
50 871 348 290 249

a ——————————————————————————

FUMIGATION

Dosages of fumigants are commonly given in ounces or pounds per
1000 cubic feet. Metric equivalents may be calculated on the basis of the

following relationship:
1 pound per 1000 cubic feet = 16.01894 milligrams per cubic decimeter
or
Milligrams per cubic decimeter
1.00118
Thus milligrams per cubic decimeter is approximately equal to ounces per
1000 cubic feet.

= ounces per 1000 cubic feet
T=

This relationship is of value in transposing laboratory dosages to
conventional units for large-scale work and in determining the concen-
tration of a fumigant, within a fumigation chamber, after proper chemical
analysis of aspirated quantitative samples.

Other conversion values for gas concentrations that may be of value
in fumigation studies are as follows:

1 cubic millimeter per cubic decimeter (liter) = 1 part per million
by volume

1 percent by volume = 10,000 parts per million

Low concentrations of fumigants or vapors in the air, where the
concentration in milligrams per cubic decimeter (liter) is determined,
sometimes are expressed directly as parts per million-#i.e., parts by
weight to a million parts by volume. Unless it is clearly explained,
such use of the expression "parts per million" is best avoided, that
statement being reserved for ratios of weight to weight or of volume to
volume.

The conversion of any weight-per-unit-volume ratio to a volume-
per-unit-volume ratio, such as parts of vaporized fumigant per million
parts of air, involves an understanding of the gram-molecular volume
relationship. This may be stated as follows: The volume of a gram-
molecule of a gas at 0OC. and 760 mm. of mercury is equal to 22.4
liters. At 25°C, and 760 mm. of mercury the volume is 24.45 liters
or 24,450 milliliters. The latter figures approximate the conditions
encountered in practical fumigation work. Conversion formulas based
on these figures are as follows:

24,450 xmilligrams per cubic decimeter

molecular weight = parts per million

Parts per = a molecular weight _ milligrams per cubic
’ decimeter

Example: A concentration of lindane vapor of 0.0006 milligram per
cubic decimeter has caused high mortality of house flies. The molecular
weight of this material is 290.85. The concentration may be expressed
in parts per million by volume as follows:

24450 x 0.0006

390.85 = 0.05 p.p.m., which is equivalent to 1 part in

20 miilion
Certain physical constants for a group of common fumigants are

presented in table 7. The figures for milliliters per pound and per
gallon have been rounded. Precise figures may be obtained by use of

the specific gravity.








ato..

Table 7, --Physical constants for several common fumigants





Pounds
per
gallon




Milliliters
per pound




Fumigant






Acrylonitrile 78 93.06 0.797 569 6.7
Carbon disulfide 46.3 76.13 1.263 359 10,5
Carbon tetrachloride 76.8 153.84 1.595 284 13,3
Chloropicrin £12 164,39 1.651 275 13.8
Dichloroethyl ether 178 143.02 1.222 onl 10.2
Ethylene dibromide 131.6 187.88 2.180 208 18.2
Ethylene dichloride 83.7 98.97 1.257 361 10.5
Ethylene oxide NOEs 44,05 0.887(109/49 511 fer
Hydrocyanic acid 26 27.03 0.688 659 9.7
Methyl bromide 4.6 94.95 1.732(00/40) 262 14,4
Trichloroethylene 87 131.40 1.477 307 12.3
MISCELLANEOUS

Capacity of Sprayer Tank

The capacity, in gallons, of the tanks on sprayers may be calculated
as follows:

Cylindrical tanks: Multiply length by square of the diameter, in
inches, by 0.0034.

Rectangular tank: Multiply length by width by depth, in inches, by
0.004329.

Tanks with elliptical cross section: Multiply length by short diameter
by long diameter, in inches, by 0.0034.

Diluting Miscible Liquids by Volume

Commercial grain alcohol of known percentage concentration can
be diluted as follows: Into a 100-ml. graduate pour as many milliliters
of the stronger solution as the percentage required in the weaker. Then
add water until the mixture reaches the milliliter mark equivalent to the
percentage of the stronger solution.

Example: To make 70-percent from 95-percent alcohol, pour into
the graduate 70 ml. of the 95-percent solution and fill to the 95-ml.
mark with water. The result is 95 ml. of a 70-percent solution.

The same procedure can be used for any other liquid, such as
acetone, that is miscible with water, and in fact for any pair of miscible

liquids.
-20-

Temperature Conversion

The two most commonly used thermometric systems are Centigrade
(C.) and Fahrenheit (F.). Equivalentsfor the two scales may be calculated
as follows:

CC. = (2 se) et saan
ORt He. eels

A number of equivalents for the two scales are presented below:







Oy, ** ee. Ve Ort OC; : Ol «, eles
pare 4 80 26.67 | 158 70
10.” <12-29) bi 86 30 TO, * “oer
14 -10 90 52.227 170° "76367
20 = - 6.67 100 ae 176 80
200 Sebi l 34 104 40 | 180 82.22
32 0 i 110 43233 190 gees
40 4.44 | 120 48.89 194 90
50 10 122 50 200 93.33
60 15-56 130 54,44 | 210 98.89
68 20 | 140 60 | 212 100
70 Zt 150 65.56

LITERATURE CITED

(1) Bearce, Henry W.
1936. United States and British units of weights and measures.
Sci. Monthly 43: 566-568.

(2) Howard, N. F., Weigel, C. A., Smith, C..M., and Stemer> 208.
1945. Insecticides and equipment for controlling insects on
fruits and vegetables. Rev. U.S. Dept. Agr. Misc.
Pub,..526;7 b6-pp.

(3) Irwin, K. G.
1951. Fathoms and feet, acres and tons: Anappraisal. Sci.
Monthly 72(1): 9-17.

(4) National Bureau of Standards
1936. Units of weight and measure (United States customary
and metric). Definitions and tables of equivalents,
/U.S./ National Bur. Standards, Misc. Pub. M 121,

68 pp.


= he

(5) National Bureau of Standards
1920. Household weights and measures. U. S. Bur. Standards,
Misc. Pub. 39, 2 pp.

(6) National Research Council
1926. International critical tables of numerical data, physics,
chemistry and technology. v. 1, pp. 1-15. New York.

(7) Smith, Floyd F.
1952. Conversion of per-acre dosages of soil insecticide to
equivalents for small units. Jour. Econ. Ent. 45:
339-340.

$$$




UNIVERSITY OF FLORIDA

MONA A

62 09224 7575