Critical Environment Technologies GEM-II, Руководство по эксплуатации

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© 2014 All rights reserved. Data subject to change without notice. 53
Rev. E | 2014.10 GEM-II - Operation Manual
8.7 Calibrating 4-20 ma for Incoming analog Transmitter
N OTE: The GEM is configured at the factory and should not require this type of calibration unless
it is not functioning properly. Specialized equipment is required; only perform these functions
after consulting the factory. This NOTE applies to Sections 8.7.1 through 8.7.4.
To perform this function, you will require either an accurate current source able to generate a 4.0
mA and 12.0 mA current signal or a CETCI analog transmitter that can supply the correct current
values.
8.7.1 Using a Current Source to Calibrate the Null
Step 1:
Connect current source to pin 10 and ground to pin-11. For zero calibration, set the current
source to 4.0 mA. Move the jumper on J6 to position-3 and the jumper on J7 to position-3.
The audible will beep once for confirmation. The system is now starting the zero calibration
stabilization time (30 seconds).
Step 2:
Attach digital multi-meter leads to test points TP-1 and TP-2. Monitor the voltage. If the audible
sounds with repetitive beeps, see Section
8.8 Forcing Calibration . The audible will beep twice
when the calibration begins. The audible beeps three times indicating the procedure is finished
(2 minutes).
Step 3:
Move jumpers from J6 & J7 back to their respective resting positions.
8.7.2 Using a Current Source to Calibrate the Span
Step 1:
Connect current source to pin 10 and ground to pin-11. For span calibration set the current
source to 20.0 mA. Move the jumper on J6 to position-3 and the jumper on J7 to position-4.
The audible will beep once for confirmation. The system is now starting the span calibration
stabilization time (30 seconds).
Step 2:
Attach digital multi-meter leads to test points TP-1 and TP-2. Monitor the voltage. If the audible
sounds with repetitive beeps. Reference Section
8.8 Forcing Calibration . The audible will beep