METHODS OF SAMPLING AXD TESTING HIGHWAY MATERIALS i O 
2. The collar (fig. 28) shall he made of brass and shall be in accordance with 
the following requirements : 
Minimum Normal Maximum 
Weight of collar, grams 
Over-all height of collar, millimeters — 
Inside diameter at bottom, millimeters. 
Inside diameter at top, millimeters 
9.60 
9.80 
10.00 
22. 3 
22.5 
22, " 
12.72 
12.82 
. . 
9.65 
9.70 
The top of the collar shall screw up tightly against the lower side of the 
shoulder. 
3. The assembled float and collar, with the collar filled flush with the bottom 
and weighted to a total weight of 53.2 grains, shall float upon water with the 
rim 8.5±1.5 millimeters above the surface of the water. Dimensions of the 
apparatus additional to those required above are given in Figure 28. 
4. The thermometer shall conform to the following requirements. These 
specifications cover a special thermometer graduated in either centigrade 
Fahrenheit degrees as specified, the ranges being —2° to 4-80 3 C. or 4-30° i - 
+180" F.. respectively. 
Type : Etched stem, glas-. 
Liquid : Mercury. 
Range and subdivision : — 1~ to 4-80° C. in 0.2° C. or 4-30° to +180° F. in 
0l5 1 F. 
Total length: 378 to 384 millimeters (14.88 to 15.12 inches > . 
Stem : Plain front, enamel back, suitable thermometer tubing. Diameter, 6 
to 7 millimeters (0.24 to 0.28 inches). 
Bulb: Corning normal or equally suitable thermometric glass. Length. 9 to 
14 millimeters (0.35 to 0.55 inch). Diameter. 4.5 to 5.5 millimeters (0.18 to 
0.22 inch i. 
Distance to 0° C. or 32° F. line from bottom of bulb: 75 to 90 millimeters 
(2.95 to 3.54 inches). 
Distance to 80° C. or 176° F. line from top of thermometer: 30 to 45 milli- 
meters (1.18 to 1.77 inches). 
Expansion chamber : To permit heating the thermometer at least 50° C. 
(90° F.) above highest temperature on scale. 
Filling above mercury : Nitrogen gas. 
Top finish : Glass ring. 
Graduation: All lines, figures, and letters clear cut and distinct. Each whole 
degree centigrade or Fahrenheit line to be longer than the remaining lines. 
Graduations to be numbered at each multiple of 2 3 C. or 5° F. 
Immersion : Total. 
Special marking: "A. S. T. M. low S. P..'" a serial number and the manu- 
facturer's name or trade-mark shall be etched on the thermometer. 
Scale error: The error at any point of the scale when the thermometer is 
standardized as provided below shall not exceed 0.2° or 0.4° F. 
Standardization : The thermometer shall be standardized immersed in the 
testing bath to the top of the mercury column, at the ice point and at tempera- 
ture intervals of approximately 20° C. or 40° F. 
Case : The thermometer shall be supplied in a suitable case on which shall 
appear the marking: -A. S. T. M. low S. P., —2 to —80° C." or "A. S. T. EL low 
S. P., 4-30 to -f ISO' P." according to the type of thermometer. 
Note. — For the purpose of interpreting these specifications the following definition 
apply : The total length is the over-all length of the finished instrument. The diameter 
is that measured with a ring gauge. The length of the bulb is the distance from the 
bottom of the bulb to the beginning of the enamel backing. The top of the thermometer 
Is the top of the finished instrument. 
5. The diameter of the bath and the depth of water shall be at least 185 
millimeters. 
PREPARATION OF SAMPLE 
0. The brass collar shall be placed with the smaller end on a brass plate 
which has been previously amalgamated with mercury by first rubbing it with a 
dilute solution of mercuric chloride or nitrate, and then with mercury. 
The sample shall be completely melted at the lowest possible temperature that 
will bring it to a sufficiently fluid condition for pouring, excepting creosote-oil 
