Envent 331S - Re-zero Sensor Procedure

Envent Engineering Ltd. Page 29 Revision 2.4
11. To adjust the gain setting such that the analyzer displays the correct H
2
S
concentration, press the right [→] and / or left [←] arrows until the cursor is
underneath the number you wish to change.
12. Adjust the number using the "Menu/Set" button (it will increase until "9" then will
cycle back through "0").
13. Save the new gain value by pressing the right arrow [→] until "Saved" appears or
discard by pressing the left [←] arrow until "Cancel" appears.
14. Allow the analyzer to complete two cycles using the new gain value. The H
2
S
reading should match the calibration gas concentration. Repeat step 10 if
necessary.
15. Return to sample gas flow using the 3-way calibration valve.
16. Set the sample gas pressure to 15 psig and set the flow meter to 2.0.
17. Disconnect the calibration gas supply.
18. After waiting 10 to 15 minutes confirm the analyzer reads below the H
2
S alarm
set points.
Remove the analyzer from bypass mode by pressing the bypass button. Verify
the "Bypass" LED turns off.
Alarms are armed after removing the bypass mode.
Re-zero Sensor Procedure
1. Press the bypass button and verify that the "Bypass" LED illuminates.
2. Turn off sample gas flow using sample inlet valve.
3. Press the "Menu/Set" button until "Mtr Run" is displayed. Press the right arrow
[→], the H
2
S sensing tape will advance for approximately 10 seconds.
4. Remove the sensor cover.
5. Press the small pushbutton on the sensor block located on the lower left side next
to the wire connector.
• The sensor block will implement a "re-zero" procedure, indicated by a lit, red
LED.
• When the "re-zero" procedure is complete the LED light will turn green.
6. Initiate another motor run (Step 3).
7. Press the "Menu/Set" button until "### mV" is displayed.
• Value should be 1000mV (+100mV)
8. Put on sensor cover.
9. Turn on sample gas flow using sample inlet valve.
10. Set the gas pressure to 15 psig and the flow meter to 2.0.