Replacing And Recalibrating The Moisture Probes; Recalibrating The Pressure Sensors - GE Moisture Image 1 Series Service Manual

June 2003
Replacing and
Recalibrating the
Moisture Probes
Recalibrating the
Pressure Sensors
2-20
For maximum accuracy you should send moisture probes back to the
factory for recalibration every six months to one year, depending on
the application. Under severe conditions you should send the probes
back for recalibration more frequently; in milder applications you do
not need to recalibrate probes as often. Contact a GE Panametrics
applications engineer for the recommended calibration frequency for
your application.
When you receive new or recalibrated probes, be sure to install and
connect them as described in Chapter 1, Installation, of the Startup
Guide. Once you have installed and connected the probes, enter the
calibration data as described in Entering Calibration Data, in Chapter
2 of the Startup Guide. Note that each probe has its own Calibration
Data Sheet with the corresponding probe serial number printed on it.
You do not have to enter calibration data for the Moisture Image
Series Probe if you returned both the sensor and the electronics
module to the factory for recalibration. However, you should verify
that the calibration data entered at the factory is correct (see page
2-12 of the Startup Guide). If you only sent the sensor part of the
Moisture Image Series Probe to the factory without the module, you
must enter the calibration data manually.
Since the pressure sensor on a TF or Moisture Image Series Probe is a
strain gage type, the pressure calibration is linear and is calibrated at
two data points. Each point consists of a pressure value and a
corresponding voltage, current, or FP value. Check or change the two
calibration points using the steps below.
1. Set one of the boxes in the matrix format to display pressure in
mV (or FP). Refer to Setting Up the Matrix Format on page 2-31
of the Programming Manual to set up the screen.
2. Expose the pressure sensor to the air and record the mV (or FP)
reading. This reading is the mV reading for the zero pressure.
3. Expose the pressure sensor to a known full scale pressure source
and record the mV (or FP) reading. This reading is the mV (or FP)
reading for the span pressure.
4. Enter the above readings in the System Calibration Menu as
described in Entering Pressure Calibration Data in Chapter 2 of
the Programming Manual.
Troubleshooting and Maintenance