46
Barometric Pressure Calibration
The barometric pressure sensor inside the
Powerbox. The channel for Barometric Pressure
was calibrated at the factory before the flowbench
was shipped. If desired, it can be calibrated to
provide more accurate readings for the actual
flowbench location.
Obtain an accurate, uncorrected barometric
pressure reading in inches/Hg from a mercury
barometer. If a mercury barometer is not available,
contact a local airport or weather service and ask
for the “local station or uncorrected pressure.”
The barometric pressure reading from the internet
or broadcast weather channel is corrected for
local elevation and therefore is not acceptable for
calibrating the sensor.
The current Barometric Pressure can be read by
reading register
40011 BarometricPressure
.
NOTICE
Calibration
1. Enable write access to calibration register for the barometric pressure transducer by setting register
40067-68 AI1_Calibration_Enable
to a value of one (
1
).
2. Enter the obtain accurate, uncorrected
barometric pressure reading in inches/Hg value
by writing it to the
40073-74 AI1_Applied
register.
3. Calibration is now complete, disable write
access to calibration register for the barometric pressure transducer by setting register
40067-68 AI1_
Calibration_Enable
back
to the default value of zero (
0
).
Figure 6.11: Baro Pressure Transducer
Baro
Pressure
Transducer
Once the calibration value is applied, the original
calibration data will be overwritten and cannot be
retrieved.
CAUTION
6.0 Maintenance
