Panametrics CTF878, Service Manual

Page: 33 / 67

Model CTF878 Service Manual 23
Chapter 3.
3.1.4.2 Calibrating Analog Inputs
The Analog Input calibration procedure consists of calibrating the analog input zero point (0 or 4 mA) and the full
scale point (20 mA).
Note: Calibrating analog inputs requires use of a current source. Calibrated analog outputs may be used as a
current source.
To calibrate an Analog Input, proceed as above, select the desired Calibrate AnalogIn option, and press [ ENTER ]. The
screen appears as in Figure 27 below. Step through the options using the arrow keys.
Figure 27: Calibrate Analog Input Window
1. The first prompt asks you to set the low input (0 or 4 mA).
a.
Press
[ENTER]
to open the text box.
b. Use the numeric keys to enter the desired value.
c. Press [ENTER] to confirm your entry.
2. Set the current source to output the current for the Low point
(0 or 4mA).
a.
Press the [

] arrow key to move to the Read box and press
[ENTER]
.
b. Scroll to the Calibrate box and press [ ENTER ] to calibrate the low point.
3. The next prompt asks for the value to which you want to set the high input (20 mA).
a.
Press
[ENTER]
to open the text box.
b. Use the numeric keys to enter the desired value.
c. Press [ENTER] to confirm your entry.
4. Set the current source to output the current for the High point
(20 mA).
a. Press the [

] arrow key to move to the Read box and press [ENTER] .
b. Scroll to the Calibrate box and press [ ENTER ] to calibrate the high point.
5. If you are unsatisfied with the calibration, you can reset the inputs to factory defaults. Press the [

] arrow key to
move to the Reset box, and then press [ENTER] to undo the calibration.
You have completed calibrating the inputs. To leave the Inputs window,
• Press [F2] (Cancel) to return to Operate Mode without confirming the changes.
• Press [F3] (OK) to confirm the new data. The CTF878 returns to Operate Mode.
Repeat the process to calibrate additional Analog Inputs.
OK Cancel
mA
Calibrate Reset
Low
High 20 mA
Read
Read
Calibrate Analog Input
4