Testing And Calibrating Analog Outputs; Testing Analog Outputs; Calibrating Analog Outputs - GE CTF878 User & Service Manual

February 2009
Testing and Calibrating
Analog Outputs

Testing Analog Outputs

Calibrating Analog
Outputs
3-2
The Calibration/Test option can be used to test and calibrate the
analog outputs. To enter the option, scroll to the Main Board or to an
AnologOut option under the Calibrate / Test Menu and press
The screen appears similar to Figure 3-2 below.
Site Program
Velocity, m/s
15.38
Corr SNR
0 50
Figure 3-2: Analog Outputs Test / Calibration Window
To test an Analog Output, you must connect a digital multimeter to
the analog output. Proceeding as above, select the Test AnalogOut
option (see Figure 3-2 above) for the Analog Output to be tested, and
press [ENTER]. A clock appears in the middle of the screen with the
message "TESTING IO" below it, while the multimeter is displaying
the test current output. The test current output value should go
through the full range. When the test is complete, the screen returns to
Operate Mode.
Repeat the process to test additional Analog Outputs.
The Analog Output calibration procedure consists of calibrating the
analog output zero point (0 or 4 mA) and then calibrating the full
scale point (20 mA). First you will enter the setpoint, and then the
actual value derived from an ammeter or digital voltmeter. The analog
outputs have a resolution of ±5.0 µA.
To calibrate an Analog Output, proceed as above, select the desired
Calibrate AnalogOut option, and press [ENTER]. The screen appears
as shown in Figure 3-3 on page 3-3. Proceed as follows:
1. Connect a digital multimeter to the analog output and step through
the options using the arrow keys.
Service
Meter Logging
Diagnostics
Signal Setup
Error Limits
Test
Factory Defaults
Flash Update
Calibrate / Test
Main Board (0)
34
AnalogIns (2)
Test AnalogOut(0:A)
Calibrate AnalogOut(0:A)
Test AnalogOut(0:B)
Calibrate AnalogOut(0:B)
[ENTER]
.
Calibration