Snap-On Motorized Loader - Manual (Page 71)

5-11
Calibration
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 Acceleration Latitude Acceleration
Degrees cm/sec2 Degrees 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