SAMPLING AND TESTING HIGHWAY MATERIALS. 53 
Special marking: "A. S. T. M. open flash." serial number, and 
manufacturers name or trade-mark etched on stem. 
Accuracy: Error at any point on scale shall not exceed one-half 
of the smallest scale division up to Too F. 
Test for permanency of range: After being subjected to a tem- 
perature of 700" P. for 24 hours the accuracy shall be within the 
limit specified. 
Points to be tested for certification: 32°, 212°, 400°, 700° F. 
PROCEDURE. 
4. (a) The thermometer shall be suspended or held in a ver- Method of test. 
tical position by any suitable device. The bottom of the bulb 
shall be one-quarter inch (0.635 centimeter j 13 from the bottom 
of the cup and above a point halfway between the center and back 
of the cup. 
(b) The cup shall be filled with the oil to be tested in such a 
manner that the top of the meniscus is exactly at the filling line 
at room temperature. The surface of the oil shall be free from 
bubbles. There shall be no oil above the filling line or on the 
outside of the apparatus. 
i c > The test flame shall be approximately five thirty-seconds 
inch (0.397 centimeter,) in diameter. 
Note. — For purposes of comparison it is recommended that a bead 
of suitable light-colored material be mounted in a convenient position 
so that the size of the test flame can be determined. The device for 
applying the flame may be of any suitable type, but it is suggested 
that the tip be approximately one-sixteenth ineh 1 0.159 centimeter) 
in diameter at the end and that the orifice be one thirty-second inch 
i 0.O79 centimeter) in diameter. If the device for operating the test 
flame be mounted in such a manner as to permit automatic duplica- 
tion of the sweep of the test flame, the radius of swing shall be not 
less than 6 inches. 
(d) The test flame shall be applied as the temperature read on 
the thermometer reaches each successive 5° F. mark. The flame 
shall pass in a straight line (or on the circumference of a circle 
having a radius of at least 6 inches) across the center of the cup 
and at right angles to the diameter passing through the ther- 
mometer. The test flame shall, while passing across the surface 
of the oil, be in the plane of the upper edge of the cup. The time 
for the passage of the test flame across the cup shall be approxi- 
mately 1 second. 
(o The rate of heating of the oil shall be such that the tem- 
perature read on the thermometer increases not less than 9° nor 
more than 11° F. per minute. 
5. The flash point shall be taken as the temperature read on 
the thermometer when a flash, appears at any point on the surface 
of the oil. The true flash must not be confused with a bluish 
halo that sometimes surrounds the test flame. 
6. After determining the flash point the heating shall be con- 
tinued at the specified rate, and application of the test flame shall 
be made at the specified intervals until the oil ignites and con- 
tinues to burn for a period of at least 5 seconds. The tempera- 
ture read when this occurs shall be taken as the fire point. 
7. The flash-point and fire-point tests shall be made in a room 
or compartment free from air drafts. The operator shall avoid 
breathing over the surface of the oil. It is desirable that the 
room or compartment be darkened sufficiently so that the flash 
may be readily discernible. 
TEST FOR PENETRATION OF BITUMINOUS MATERIALS. 
(A. S. T. M. standard method, serial designation D 5-21, slightly modi- 
fied.) 
I. DEFINITION. 
1. Penetration is defined as the consistency of a hi luminous ma- 
terial, expressed as the distance that a standard needle vertically 
13 The immersion line engraved on the thermometer stein will be one- 
sixteenth inch (0.150 centimeter) below the level of the rim of tbe cup. 
