Rice Lake 120 Plus Digital Weight Indicator - Manual (Page 50)

46 120Plus Digital Weight Indicator Technical Manual
8.6 Gravity Compensation
This feature is used to compensate for the variance in gravitational pull from one location to another and is
available for the 120+. To calibrate with gravity compensation, the GRAVADJ parameter must be set to ON,
and the LATITUD (latitude in degree) and ELEVATN (elevation in meters, relative to sea level) parameters
set before calibrating the 120+.
If the indicator is later installed at a different location, gravity compensation can be applied to a pre-calibrated
120+ by adjusting the LATITUD and ELEVATN parameters.
Gravity is greater at the poles than at the equator and decreases with increase in altitude. The effect of
gravity at any given location can be calculated using the following formula:-
g CAL = 9.80632 - 0.0258Cos(0.0349065850Ø CAL ) + 0.00003Cos(0.00698131701Ø) - 0.00000293h CAL (EQ 1)
gOpa = 9.80632 - 0.0258Cos(0.0349065850ØO PA ) + 0.00003Cos(0.00698131701Ø) - 0.00000293hO PA (EQ 2)
Where Ø = degrees latitude and h = height in meters
For example:
Calibration location at Canada Magog, and Operation location at Taiwan Taipei.
The geographic data and calculation:
That means a mass at operation location, ever one kilogram more 1.74 gram. In this way,
the same mass will weight in both location is same.
8.7 Summary of Changes
Changes to recent editions of this manual are listed below:
Version 1.07
Added information on the following parameters:
• Gravity Adjust - which includes latitude and elevation parameters.
• Information has been added in Section 3.3 - Calibration Menu
• Information has been added in Section 3.5 - Program Menu
• Section 8.6 Section on Gravity Compensation
W
Opa =
W
CAL
g
Opa
g
CAL
if GRAVADJ = ON
W
Opa =
W
CAL
if GRAVADJ = OFF
W
Opa =
W
CAL
g
Opa
g
CAL
Magog: = 45° and h = 222m, Taipei: = 23° and h = 10m
= 9.80564, = 9.78836
9.78836
9.80564
= 1.00174
W
CAL
Ш Ш