SPECIFICATIONS FOR BITUMINOUS ROAD MATERIALS. 57 
( & ) Thermometer : The thermometer shall conform to the following require- 
ments : 
It shall be made of thermometric glass of a quality equivalent to suitable 
grades of Jena or Corning make. It shall be thoroughly annealed. It shall be 
filled above the mercury with inert gas which will not act chemically on or 
contaminate the mercury. The pressure of the gas shall be sufficient to pre- 
vent separation of the mercury column at all temperatures of the scale. There 
shall be a reservoir above the final graduation large enough so that the pressure 
will not become excessive at the highest temperature. The thermometer shall 
be finished at the top with a small glass ring or button suitable for attaching 
a tag. Each thermometer shall have for identification the maker's name, a 
serial number, and the letters "A. S. T. M. Distillation." 
The thermometer shall be graduated from to 400° C. at intervals of 1° C. 
Every fifth graduation shall be longer than the intermediate ones, and every 
tenth graduation beginning at zero shall be numbered. The graduation marks 
and numbers shall be clear-cut and distinct. 
The thermometer shall conform to the following dimensions: 
Total length, maximum, 385 mm. 
Diameter of stem, 7 mm. ; permissible variation, 0.5 mm. 
Diameter of bulb, minimum. 5mm. ; and shall not exceed diameter of stem. 
Length of bulb, 12.5 mm. ; permissible variation, 2.5 mm. 
Distance from 0° to bottom of bulb, 30 mm. ; permissible variation, 5 mm. 
Distance from 0° to 400°, 295 mm. ; permissible variation, 10 mm. 
The accuracy of the thermometer when delivered to the purchaser shall be 
such that when tested at full immersion the maximum error from to 200° C. 
shall not exceed the following : 
From to 200° C 0°. 5 C. 
From 200 to 300° C 1°.0C. 
From 300 to 375° G 1°.5C. 
The sensitiveness of the thermometer shall be such that when cooled to a 
temperature of 74° C. below the boiling point of water at the barometric pres- 
sure, at the time of test, and plunged into free flow of stream, the meniscus 
shall pass the point 10° C. below the boiling point of water in not more than 
six seconds. 
The thermometer shall be set up as for the distillation test, using water, 
naphthalene and benzophenone as distilling liquids. The correctness of the 
thermometer shall be checked at and 100° C. after each third distillation until 
seasoned. 
( c ) Condenser : The condenser tube shall have the following dimensions : 
Adapter mm__ 70 
Length of straight tube " 185 
Width of tube " 12-15 
Width of adapter end of tube " 20-25 
(<T) Stands: Two iron stands shall be provided, one with a universal clamp 
for holding the condenser, and one with a light grip arm with a cork-lined clamp 
for holding flask. 
(e) Burner and shield: A Bunsen burner shall be provided, with a tin 
shield 20 cm. long by 9 cm. in diameter. The shield shall have a small hole for 
observing the flame. 
(/) Cylinders: The cylinders used in collecting the distillate shall have a ca- 
pacity of 25 cc, and shall be graduated in 0.1 cc. 
4. Setting up the apparatus. — The apparatus shall be set up as shown in 
figure 8, the thermometer being placed so that the top of the bulb is opposite 
the middle of the tubulature. All connections should be tight. 
