Teledyne 2230R - Process Hydrogen Analyzer - Manual (Page 24)

MODEL 2230R, Process Hydrogen Analyzer
Page 24
5.5 CALIBRATION
Calibration Interval
Calibration is used to correct any offset that exist between the sensor output and a known
hydrogen concentration. Calibrations do not cause any wear on the sensor and can be
accomplished as often as desired. It is recommended that Calibration be performed if a unit
fails Verification.
Calibration Procedure
IMPORTANT NOTE: During the Calibration process any previously completed Field Calibrations
are cancelled. As a result, during the routine the unit may display a hydrogen concentration
that is different from the applied gas concentration. This is normal. Once the procedure is
completed, the readings will be corrected to display the right concentrations for all subsequent
exposures.
Calibration can only be accomplished through interface with the unit via the serial port (refer to
the previous Serial Communication Commands section and the LEVEL 1 COMMANDS table in
Section 4.3). Analog outputs can be monitored through the user’s system.
Calibration Using Serial Interface (firmware version 0.47) – Follow the sequence below:
1) Press “Esc”
2) The unit will return the command prompt “H2scan:”
3) Type “f” then hit “Enter” and follow prompts to field calibrate the sensor with two gas
concentrations
These steps will implement the following specification values as an example; for values in bold,
please substitute appropriate values relative to your specific operational conditions:
• Local atmospheric pressure: 0.969 ATM
• Hydrogen range: 0% to 30% hydrogen, balance nitrogen
• Field Verification Gas #1: 1% hydrogen, balance nitrogen (instead of gas #1 being 0%
hydrogen, H2scan recommends Field Verification gases always have a hydrogen
concentration)
• Field Verification Gas #2: 30% hydrogen, balance nitrogen
• Settle Time: 30 minutes (TELEDYNE ANALYTICAL INSTRUMENTS recommends this
duration for field calibration)
WARNING: AS IN THIS EXAMPLE, FOR OPTIMIZATION, THE HYDROGEN
CONCENTRATIONS OF THE GASES IMPLEMENTED IN FIELD CALIBRATION
AND FIELD VERIFICATION MUST BE THE SAME.