Watlow ez-zone pm - Page 191

Watlow EZ-ZONE
®
PMI Controller • 187 • Chapter 9 Features
Note:
The user may only calibrate one sensor type. If the calibrator interferes with open ther-
mocouple detection, set Sensor Type sEn in Setup Page sEt, Analog Input Menu ai to
millivolt ЛЏu instead of Thermocouple tC to avoid interference between the calibrator
and open thermocouple detect circuit for the duration of the calibration process. Be sure
to set sensor type back to the thermocouple type utilized.
1. Disconnect the sensor from the controller.
2. Record the Calibration Offset i.Ca parameter value in the Operations Page opEr, Analog
Input Menu ai then set value to zero.
3. Wire the precision source to the appropriate controller input terminals to be calibrated.
Do not have any other wires connected to the input terminals. Please refer to the Install
and Wiring section of this manual for the appropriate connections.
4. Ensure the controller sensor type is programmed to the appropriate Sensor Type sEn to
be utilized in the Setup Page sEt, Analog Input Menu ai.
5. Enter Factory Page fCty, Calibration Menu CaL via front panel or EZ-ZONE Congurator
Software.
6. Select the Calibration CaL input instance to be calibrated. This corresponds to the analog
input to be calibrated.
7. Set Electrical Input Slope ELi.s to 1.000 and Electrical Input Offset ELi.o to 0.000 (this
will cancel any prior user calibration values)
8. Input a Precision Source Low value. Read Electrical Measurement value ЛЏu of controller
via EZ-Congurator or RUI. This will be referred to as Electrical Measured Low. Record low
value ______________
9. Input a Precision Source High value.
10. Read Electrical Measurement value ЛЏu of controller via EZ-Congurator or RUI. This will
be referred to as Electrical Measured High. Record high value ______________
11. Calculated Electrical Input Slope = (Precision High – Precision Low) / (Electrical Mea-
sured High - Electrical Measured Low) Calculated Slope value ___________
12. Calculated Electrical Input Offset = Precision Low - (Electrical Input Slope * Measured
Low) Calculated Offset value ___________
13. Enter the calculated Electrical Input Slope ELi.s and Electrical Input Offset ELi.o into
the controller.
14. Exit calibration menu.
15. Validate calibration process by utilizing a calibrator to the analog input.
16. Enter calibration offset as recorded in step 2 if required to compensate for sensor error.
Setting Electrical Input Slope ELi.s to 1.000 and Electrical Input Offset ELI.o to 0.000, re-
stores factory calibration as shipped from factory.