Salter Brecknell 7840 - Manual (Page 27)

Model 7800 Family Weight Classifiers User’s Manual 27
Gravity Mode
The CAL-GR and
LOC-GR values may
be viewed anytime.
See Review/Test
Scale Setting section.
Warning: Using this
feature in “sealed”
applications may be
subject to approval by
the appropriate
governing agency
at the end-users site.
Gravity value roles
‘over’ at 9.8400 and
rolls ‘under’ at 9.7700.
The Gravity Mode feature provides a means of
adjusting the scale’s internal calibration factors to
compensate for variations in acceleration due to
gravity at different geographic locations. These
differences can cause a given mass to indicate a
slightly different weight at an end-user’s (local)
site than it did at the Calibration (CAL) site.
To make the adjustment, you must know the
value of the gravity constant for the local site.
This value is expressed in meters per second,
per second (i.e., m/s
2 ). It is not necessary to
calibrate the scale, therefore, no calibration
weights are needed to make this adjustment.
The scale maintains two gravity setting values.
The first is the “calibration-site” value known as
CAL-GR. The second is the end-user or “local-
site” value and is known as LOC-Gr. When the
scale was originally calibrated at the factory, the
CAL-GR and LOC-GR values were both set to
9.8040 which is the gravity constant for the
manufacturing site.
To adjust the displayed weight value, you must
enter the local gravity value.
To enter the Gravity Mode, set Switch 2 to the
OPEN position. The display will indicate the
current “local” gravity value. Press the ZERO key
to increment the value or the TEST key to
decrement the value. The gravity value will
change in steps of .0002. When the correct value
is displayed, simply return Switch 2 to the
CLOSED position. The scale will now use this
new relationship between calibration and local
gravity for its weight calculations.