Envent Engineering Ltd. Page 35 Revision 2.4
H2S Readings Issues (Cont’d)
Contaminants in sample
chamber
Clean sample chamber, aperture and
window; replace if required. Contact Envent
Engineering Ltd for replacement assistance.
Contaminants or liquid carry
over in sample conditioning
system
If contaminants or liquid has carried over
the sample system, refer to page 32.
Humidifier leaking Humidifier needs to either be repaired or
replaced. Consult Envent Engineering Ltd.
Possible high pressure in flare
line (Dilution option only)
Install a higher rated check valve.
Slow response Aperture in chamber not
optimized for required range
Consult "Aperture Strip" on page 19 for
aperture size and contact Envent
Engineering Ltd to order aperture and for
assistance to install new aperture and re-
calibrate analyzer. Refer to "H
2
S Gas
Calibration" on page 28.
Contaminants or liquid carry
over in sample conditioning
system
If contaminants or liquid has carried over
the sample system, refer to page 32.
Higher than
Expected
Readings
Sample vent/Eductor either
blocked or frozen
Check there is no blockage on the vent
and/or eductor. Check for vacuum in
Eductor block
Vent tubing and fittings should be 316
stainless steel 3/8'' or larger on a downward
slope. Possible heat trace required.
Contaminants in sample
chamber
Clean sample chamber, aperture and
window; replace if required. Contact Envent
Engineering Ltd for replacement assistance.
Aperture out of place or not
optimized for required range
Remove the sample chamber, unscrew the
sensor block and check that the aperture is
not out of place. Consult "Aperture Strip" on
page 19 for aperture size and "H
2
S Gas
Calibration" on page 28. Contact Envent
Engineering Ltd to order aperture (if
applicable) and for assistance to install new
aperture and re-calibrate analyzer.
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