METHODS OF SAMPLING AND TESTING HIGHWAY MATERIALS 79 
Top finish: Glass ring. 
Graduation: All Hues, figures, aud letters clear cut and distinct. The first 
and each succeeding 5° C. or 10° F. line to be longer than the remaining lines. 
Graduations to be numbered at each multiple of 10° C. or 20° F. 
Immersion : Total. 
Special marking: "A. S. T. M. high distillation." a serial number, and the 
manufacturers name or trade-mark shall be etched on the stem. 
Scale error: The error at any point of the scale up to 370° C. or TOO' F. 
when the thermometer is standardized as provided below shall not exceed 1° 
C. or 2° F. 
Standardization: The tbermometer shall be standardized immersed in the 
testing bath to the top of the mercury column, at the ice point, and at temper- 
ature intervals of approximately 50° C. or 100° F. up to 370° C or TOO 3 F. 
3.2 mm. 
iO.lmm. 
|< 105 mm i 2mm.— >j 
r 
E 
lis 
h- I 
[•■I6mm.±2mm. 
I 38mm. 
"^t/Smmf" 
136 mm. ±3 mm. 
I 
T~ 
Cover 
Shield. 
Flanged Open-End Cylinder 
Made of 22 gage Galvanized 
Iron with ±-in. Asbestos Lining 
Riveted to Metal 
FIG. 31.— Shield 
Test for permanency of range: After being subjected to a temperature be- 
tween 360° and 3To° C. or 680° and TOO F. for 24 hours, the accuracy shall be 
within the limit specified. 
Case: The thermometer shall be supplied in a suitable case, on which shall 
appear the marking: "A. S. T. M. high distillation, 0° to 400° C." or "A. S. T. M. 
high distillation. 30° to T60° F.." according to the type of thermometer. 
Xote. — For the purpose of interpreting' these specifications. the following definitions 
apply: Tne total length is the over-all length of the finished instrument. The diameter 
is that measured with a ring gage. The length of the bulb is the distance fr >m the 
bottom of the bulb to the beginning of the enamel backing. The top of the thermometer 
is the top of the finished instrument. 
