METHODS OF SAMPLING AND TESTING HIGHWAY MATERIALS 105 
8. Quantity of solution. — Wire samples shall be tested in a glass jar of at Least 
2 inches inside diameter. The jar without the wire samples shall be filled with 
standard solution to a depth of at least 4 inches. 
9. Solution shall not be used for more than one series of four immersions. 
10. Samples.— X.r more than seven wires shall be simultaneously immersed in 
the specified quantity of solution. 
11. The sample shall not be grouped or twisted together but shall be well 
separated so as to permit the action of the solution to be uniform upon all 
immersed portions of the samples. 
12. Test.— Clean and dry samples shall be immersed in the required quantity 
of standard solution in accordance with the cycle of immersions called for in 
the specifications. 
13. The temperature of the solution shall be maintained between 62° and 
F. at all times during the test. 
14. After each immersion the samples shall be immediately washed in clean 
water having a temperature between 62° and 6S° F. and wiped dry with 
cotton waste. 
15. Rejection. — If after the test described in paragraphs 12. 13. and 14 there 
should be a bright metallic copper deposit upon the samples, the lot represented 
by the samples shall be rejected. 
lf>. Copper deposits on zinc or within 1 inch of the cut end shall not be 
considered causes for rejection. 
17. In case of a failure of only one wire in a group of seven wires immersed 
together, or if there is a reasonable doubt as to the copper deposit, two check 
tests shall be made on these seven wires and the lot reported in accordance with 
the majority of the sets of tests. 
Note. — The equipment necessary for the tf sT herein outlined is as follows : 
Commercial copper-sulphate crystals. 
Chemically pure cupric oxide (CuO). 
Running water. 
Warm water or ice, as per needs. 
Carbona. benzine, or turpentine 
Glass jars at least 2 inches inside diameter 
by at least 4% inches high. 
Glass or earthenware jars for hardware 
samples. 
Vessel for washing samples. 
Tray for holding jars of stock solution. 
Jars, bottles, and porcelain basket for stock 
solution. 
Cotton waste. 
Hydrometer cylinder .°> inches in diameter 
by 15 inches high. 
Thermometer with large Fahrenheit scale 
correct at 62° and 68°. 
Hydrometer correct at 1.186 at 65° F. 
Filter paper. 
67. STANDARD METHODS OF VERIFICATION OF TESTING 
MACHINES 
(A. S. T. M. standard method (.3), serial designation E 4-27) 
DEFINITIONS 
1. (a) Testing machine. — A mechanical device for applying a load (forced to 
a specimen. +s 
(6) Error. — In the case of a testing machine, the value obtained by subtract- 
ing the correct value of the quantity measured (usually load) from the indi- 
cated value as giveo by the testing machine. 49 
(e) Percentage of error. — In the case of a testing machine, the ratio, expressed 
in per cent, of the error to the correct value of the quantity measured. 
(d) Correction. — In the case of a testing machine, the value obtained by 
subtracting the indicated value from the correct value of the quantity measured. 
Note— The correction has the same magnitude as the error but the opposite sign. It 
is recommended that, except for special cases, no corrections be used on machines tested 
and found to have errors within the tolerances given in these methods. 
(e) Tolerance. — In the case of a testing machine, the maximum allowable 
error in the value of the quantity indicated. 
Note. — It is convenient to express tolerance in terms of percentage of error. The 
numerical value of the tolerance for a te-riiu: machine is so >tated hereafter in These 
methods. 
45 Usually the magnitude of the load can be changed at the will of the operator. 
Many testing machines are arranged to measure The load, but This is not always the 
case, especially with impact machines and machines for testing ductility. 
a - The error may be positive or negative. 
