Reid Vapor Pressure Apparatus

TM 5-6640-213-14

NOTE

If a tared weighing boat is used, remove the tare

ring and zero with the empty boat on the pan.

5. Weighing to a present weight is also a capa-

bility of the balance. Adjust the weight control knobs and, if

necessary, the micrometer drum knob to the desired value. Preweigh

step 3., move the arresting lever to the full-release position and

adjust the weight by use of filter paper or a glass rod until the

value is reached.

6. Correction of the weighing result can be made

for conditions requiring absolute weighings. The switching weights

are made of noncorrosive, nonmagnetic steel having a density of 7.88

g per ml. For a medium air density of 0.0012 g per roil, they are

adjusted to match brass weights of density 8.4 g per ml. Differ-

ential weighings of the same material do not require correction. In

case of absolute weighings, the result of the following formular has

to be added to the weighting result:

(1.61 m) - pl/pg + pl/pp

K (grams)

Herein:

reading of the

balance in g,

the density of

the air in g/ml

the density of

the switching weights in g/ml,

the density of

the weighing material in g/ml

(3) Reid Vapor Pressure Apparatus.

(a) Description. The Reid vapor pressure (RVP)

apparatus (fig. 2-8), designed and constructed to comply with ASTM

test for RVP of petroleum (D-323), is mounted in the far right-hand

corner of the laboratory within the laboratory table. The apparatus

includes a stainless-steel, constant-temperature bath that is flush

mounted in the tabletop. Over the bath are mounted a l/3-horsepower

motor, a thermometer, a 500-watt "low lag" immersion heater con-

trolled by a microset thermoregulator, and brackets for suspending

the bombs. A standpipe stoppered drain is threaded into the bottom

of the bath. The line switch, pilot light and electronic relay are

mounted on a bar under the tank section of the bath assembly. The

thermoregulator is adjustable. The maximum current carrying capacity

is 15 milliamperes (ma).

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