ADCS-601-AF™ OPERATION AND MAINTENANCE MANUAL
© 2005 - 2007 DH Instruments, a Fluke Company
Page 146
Figure 61.
ADCS Tools CDG Zero System Display
7.2.7
PG7601, ADJUST ON-BOARD P, T, H SENSORS
The PG7601 Platform includes sensors to measure ambient conditions. The values
measured are used to calculate ambient air density which is used to make the air buoyancy
correction to the force applied by the PG7601 masses in gauge mode. The measurements of
the ambient conditions sensors have no function when the PG7601 is used in absolute
measurement mode.
The on-board measurement sensors and their measurement uncertainty tolerances are:
•
Barometric pressure sensor, ± 140 Pa
•
Relative humidity sensor, ± 10 % RH
•
Ambient temperature sensor: ± 1 ºC
The ambient conditions sensors are verified and adjusted relative to a reference without
being removed from the platform. The measurement uncertainty specification of the on-
board sensor should be taken into consideration when selecting a reference relative to which
to adjust them.
The sensors are adjusted using
[Maintenance]
,
[PG Sensors]
in
ADCS Tools
(see Figure 62).
The
PG Sensors Adjust
form allows the current output of each sensor to be viewed. Each
sensor’s output can be adjusted by changing the value of an adder and/or multiplier that are
used to offset and adjust the slope of the sensor’s output. The adder and multiplier adjust the
sensor output as follows:
Corrected Output = (Measured Output X Multiplier) + Adder
Where:
•
Corrected output, measured output and adder are in the current unit of measure of the
sensor
•
Multiplier is dimensionless
•
Normally, it is sufficient to offset the sensor’s output relative to the reference using the
adder only.
