TB 9-6685-319-35
(6) Place enough deadweights on applicable low or high pressure piston to obtain
the 90 percent cardinal point of TI. Refer to table 4 for conversion table.
Table 4. Conversion Table
Number of deadweights
Value of each
1 weight equal the equivalent pressure
supplied with pressure
weight
(psi)1
gage tester (ea)
(lbs)
Low Pressure Piston
High Pressure Piston
18
10
100
500
1
9 1/2
95
475
4
2
20
100
4
1/2
5
25
lPressure
generated by deadweight testers are affected by acceleration of gravity. Mansfield and Green, Model 10-1025
deadweight tester generates true pressures at locations where the acceleration of gravity is 980.217 cm/s2. The acceleration of
gravity must be considered when using the deadweight tester to calibrate TI's with an accuracy of 0.35% of FS or better. To
correct for the effect of gravity, multiply total pressure of weight combination by local gravity (units -cm/s2) and divide by
980.217 cm/s2.
(7) Repeat (4) above.
(8) If TI does not indicate within limits calculated in (2) above perform b below.
(9) Repeat (2) and (6) through (8) above, using enough weights to obtain cardinal
points nearest to 80, 60, 40, 20, and 10 percent of TI scale.
(10) Thoroughly clean TI in accordance with paragraph 7 above.
b. Adjustments (Typical, fig. 2)
Figure 2. Typical pressure gage.
6