38 of 66 Calibrations - 3654 Portable H2/N2 Analyzer
Operator Manual
ORBISPHERE
The sensor can be calibrated in pure H2 or N2 gas at atmospheric pressure.
WARNING
Handle H2 gas with great care. It is extremely flammable and explosive.
To ensure that the flow chamber and sensor components are dry, remove and blow dry
the flow chamber. Dry the sensor head surface with a clean soft tissue.
The analyzer uses an internal barometric pressure sensor during this calibration. First
check that the pressure sensor is correct and does not need recalibrating. If it does need
to be recalibrated then follow the instructions in “Barometric Pressure Sensor
Calibration” on page 35 before attempting this calibration.
1) Set the gas measurement phase to Gaseous and set the calibration medium to
In measured pure gas at atmospheric pressure (as detailed in “Calibration
Medium” on page 32).
2) Connect a source of pure H2 or N2 gas to the inlet of the flow chamber, as
illustrated in Fig 4-2 on page 37, and adjust the gas flow to one bubble per
second when the exit tube is immersed in water.
3) Press the CAL button. Remember, this button may have been locked out to
prevent an accidental reset (see “Locking Out the Instrument’s CAL Button” on
page 32 for details).
4) Press the CAL button. Remember, this
button may have been locked out to
prevent an accidental reset (see “Locking
Out the Instrument’s CAL Button” on
page 32 for details).
5) A brief clearing message [---]
appears.
6) Press CAL again within a 3 second
period.
If the instrument makes two consecutive
measurements with less than 1%
difference, it calibrates against this
stabilized value. The LCD then displays
the message [CAL] to indicate
calibration has been successfully
completed
If the calibration does not complete, the
LCD displays the message [Err]. The
reason for this calibration error is either
that the measured gas partial pressure is
under 5 mbar, or that a wrong instrument
key was pressed during the calibration
steps.