INFICON Sensistor ISH2000P Hydrogen Leak Detector, Panel Model - Manual (Page 22)

Hydrogen leak detector Sensistor ISH2000 - Operating Instructions
20 OP-Sensistor ISH2000-EN-201203
EN
Note: If calibration fails you can still use the instrument. Last valid calibration
parameters will be used. You should, however, check that the instrument
reacts to the reference.
Reference Value
Your reference should have a concentration or flow equal to or slightly above what
you want to measure. See the examples below for specific recommendations.
Example for reference gas:
• Reject level is set at 8 PPM
• For good accuracy, use a reference gas between 5-400 ppm hydrogen.
• 8 PPM hydrogen in synthetic air will give best results.
Example for reference leak
• Reject Level is set at 2.0E-4 atm. cc/s
• For best accuracy reference leak within 2.0E-4 - 2.0E-3 atm cc/s.
• A reference leak calibrated to 2.0E-4 atm. cc/s will give best accuracy.
Reference Unit
The Reference Unit is set in the Calibration menu. Select PPM, cc/s, cc/min, SCCM, g/a,
oz/yr, mbarl/s, mm3/min, Pa m3/s or Custom. When you select Custom you can enter
any unit as long as it contains a maximun of 12 characters.
Calibration can be performed with:
• a known hydrogen concentration
• a known flow leak
The following characters can be used: Upper and lower case Roman letters, the
numbers ь,
ь, Е, Д,Ц, е,д,ц,%,/,(,),and - (dash).
Note: The space (““) is not supported. The leak rate unit string will be cut short at
the first space found. See “Engineering format” on page 17.
Calibration Time
The calibration time decides how long time the detector looks for a reference signal
before giving up. If the calibration is set to, for example, 6 seconds the detector will
Sensitivity too low for
Reject level Sensitivity of sensor is too
low to guarantee correct
response to a gas flow or
concentration equal to
the Reject level. The most
likely reason is that
sensor is too old. Check reference. Gas
valve may be shut.
Check that probe tip is
not clogged.
Check setting of Reject
Level.
Replace sensor if problem
remains.
High signal! Check
reference! Reference signal is
abnormally high. Check that reference gas
mix is not replaced with
tracer gas mix.
Check condition of
reference.
Check that reference leak
connections has no leaks.
Message Explanation Remedy