1 BULLETIN 1216, U. S. DEPABTMENT OF kGRICUUTUKEi. 
Method »f 14. (a) The investigator should realize that Pew, if any, natural 
sampling. sand and gravel deposits arc uniform, and when a sample is 
taken the quantity of material in the deposit similar to the sam- 
ple shall be ascertained as nearly as possible. 
(b) If possible, samples of sand shall be taken when it is in 
a damp condition. 
(c) If the deposit is worked as a bank or pit and has an open 
face, the sample shall be taken by channeling the open face so 
as to represent all material suitable for use as determined by a 
visual examination. Care shall be taken to eliminate any over- 
burden or stripping at the top and any material that has fallen 
along the face from the top. It is necessary, especially in small 
deposits, to excavate test pits some distance back of and in a 
line parallel to the face to determine the extent of the supply. 
The number and depth of these pits will depend upon the quantity 
of material that is to be taken from the deposit Separate sam- 
ples shall be taken from the face of the bank and from the test 
pits. These shall be well mixed to form a composite sample and 
the sample for testing shall be obtained by the quartering method, 
(d) Deposits that have no open face shall be sampled by means 
of test pits. The number and depth of these pits will depend upon 
local conditions and the amount of material to be used from the 
source. A separate sample shall be taken from each pit and where 
visual examination indicates there is no radical difference in 
size of grain, color, etc., the several samples shall be well mixed 
to form a composite sample and the sample for testing shall be 
obtained by the quartering method. Where visual examination 
indicates there is a distinct difference in material from different 
pits, separate samples shall be taken for testing. 
(e) It is suggested that the colorimetric test be used for deter- 
mining the percentage of organic material. 3 
15. In addition to the general information accompanying all 
samples from sand and gravel deposits which are not commercial 
sources, detailed information shall be supplied similar to that 
specified to be furnished with samples of stone taken from local 
ledges. 
B. Sampling of Sand and Gravel from Commercial Plants. 
Method of I®. Samples of both sand and gravel from commercial screening 
sampling or wa -Shing plants shall be taken from the bins or storage piles 
preferably while the material is being loaded from these supplies. 
The sand and gravel shall be sampled as separate units and ship- 
ped as such. It is difficult to secure a representative sample from 
stock piles and bins and. if conditions require sampling from these 
sources, the following is recommended : Separate samples shall be 
taken from different parts of the stock pile, care being taken to 
avoid sampling a segregated area of coarse-grained material which 
is likely to exist at the base of the pile. In sampling from a bin, 
separate samples shall be taken from the top and the loading 
chute. At the latter place at least one-half cubic yard of material 
shall be run off and representative samples taken from it. These 
separate samples shall be well mixed to form a composite sample 
and the sample for testing shall be obtained by the quartering 
method. 
17. The size of sand and gravel will be affected by the same 
factors as broken stone and the same Inspection is necessary. In 
addition, the relative amount of water used in screening must be 
taken into consideration. The same procedure for taking a sample 
of broken stone for size is recommended for sampling sand and 
gravel for size, both at plant and at delivery. 
18. Where it is not practicable to visit the plant, samples for 
both quality and size shall be taken from different parts of the 
2 For a description of this tent. Bee the Standard Method of Tost for 
Organic Imparities in Sands for Concrete, serial designation, C 40-22, of 
the American Society for Testing Materials. 
