Instruction Manual
D103785X012
Calibration
June 2017
44
Manual Calibration
Two procedures are available to manually calibrate travel:
D Analog Adjust— This procedure is used when you can manually change the 4-20 mA current source to move the
valve.
D Digital Adjust— This procedure is used when the 4-20 mA current source cannot be manually changed.
Analog Calibration Adjust
Connect a variable current source to the instrument LOOP + and LOOP - terminals. The current source should be
capable of generating 4 to 20 mA.
Follow the prompts on the Field Communicator display to calibrate the instrument's travel in percent.
Note
0% Travel = Valve Closed
100% Travel = Valve Open
1. Adjust the input current until the valve is near mid‐travel. Press OK.
Note
In steps 2 through 7 the accuracy of the current source adjustment affects the position accuracy.
2. Adjust the current source until the valve is at 0% travel, then press OK.
3. Adjust the current source until the valve is at 100% travel, then press OK.
4. Adjust the current source until the valve is at 0% travel, then press OK.
5. Adjust the current source until the valve is at 100% travel, then press OK.
6. Adjust the current source until the valve is at 5% travel, then press OK.
7. Adjust the current source until the valve is at 95% travel, then press OK.
8. Place the instrument In Service and verify that the travel properly tracks the current source.
Digital Calibration Adjust
Connect a variable current source to the instrument LOOP + and LOOP - terminals. The current source should be set
between 4 and 20 mA.
Follow the prompts on the Field Communicator display to calibrate the instrument's travel in percent.
1. Adjust the input current until the valve is near mid‐travel. Press OK.
Note
0% Travel = Valve Closed
100% Travel = Valve Open
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