MODEL 2230R, Process Hydrogen Analyzer
5.5CALIBRATION
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.
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