Honeywell VA201T Calibration Handbook page 112

Calibration Handbook
Specify gas concentration value. Defaults are 50% LEL: for 2.5% methane or 50% UEG: for 2.2% methane.
Use ST to change displayed gas value in 1% steps to gas concentration used.
23. Press ; display shows
Fit gassing cover over weather protection of unit then apply span gas at one liter/minute and wait for
reading to stabilize approximately 30 sec to 1 min.
24. When gas reading stabilizes, press
25. If successful, after 10 seconds display shows
26. Wait for process to complete and display shows
27. Remove gassing cover from weather protection. Ensure reading has returned to 00.0% LEL then press
; display shows
Releases analog output from 2mA (inhibit signal) to normal operation (4mA)
28. Press and hold
Analog output is returned to normal operation
29. Aftrer the 4-20 inhibit is released, wait and display returns to Calibrate Menu. Press ESC twice to return
to Main Menu.
30. Turn off Handheld Interrogator by pressing ESC and

Press Enter when
Stable: XX.X
; display shows
Processing Data
Please Wait . . .
Span Calibrated
Remove Gas, Press
Press Enter to
Release 4-20
; for 3 sec, display shows
4-20 Released
Span Gas
50 % LEL
Enter: XX.X
together.
112 Searchpoint Optima Plus