MANUAL LOADER CHAPTER 6
6-56
Gravitational Effects
Correction Factors on Test Weights
Weights used in torque calibration are affected by their acceleration due to:
• Altitude above or below sea level, and
• Latitude on earth between the equator and the poles.
Test bars are not affected by these conditions. The accuracy of torque wrenches
and testers does not change due to changes in geographic location. Only when
using weights must correction factors be considered. After an analysis is made
for a given location, it is often found that the correction factor is insignificant.
Two methods of correction are provided. They are:
• Correction factor for check point readings adjusts the calibration readings
without changing the applied weight.
• Correction factor for weights adjusts the weight applied without changing check
point readings. For additional information refer to Gravitational Charts in this
chapter.
Gravitational Charts
The charts in this section are taken from CRC Handbook of Chemistry and
Physics, 58th Edition. CRC Press, Inc., 18901 Cranswood Parkway. Cleveland,
Ohio 44128.
Acceleration Due to Gravity for Sea Level at Various
Latitudes
Latitude, degrees Acceleration, cm/sec2 Latitude, degrees
Acceleration, cm/sec2
0 978.039 46 980.711
5 978.078 48 980.892
10 978.195 50 981.071
15 978.384 52 981.247
20 978.641 54 981.422
25 978.960 56 981.592
30 979.329 58 981.757
32 979.487 60 981.918
34 979.652 65 982.288
36 979.822 70 982.608
38 979.995 75 982.868
40 980.171 80 983.059
42 980.350 85 983.178
44 980.531 90 983.217
Free Air Correction for Altitude
Altitude, m Correction, cm/sec2
200 -0.0617
300 -0.0926
400 -0.1234
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