Hach 3654 Portable H2/N2 Analyzer manual Calibrating In a Liquid H2 or N2 Solution

40 of 66 Calibrations - 3654 Portable H2/N2 Analyzer

4.2.4 Calibrating In a Liquid H2 or N2 Solution

The sensor can be calibrated in a standard liquid solution that has a known concentration of H2 or N2. You can create a solution with a known concentration by dissolving H2 or N2 in water at a measured temperature and pressure. Alternatively, analyze a carbonated beverage independently by some acceptable means.

1) Set the gas measurement phase to Dissolved and set the calibration medium to In a liquid or a gaseous sample at known concentration (as detailed in “Calibration Medium” on page 32).

2) 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).

3) A brief clearing [---]message appears.

4) Press CAL again within a 3 second period. The instrument then displays the concentration of H2 or N2, based on the last value of the calibration coefficient.

5) Modify this reading using the Up/Down Arrow keys until the displayed concentration agrees with that of the calibration solution.

6) Press CAL again.

7) Start the flow of the standard (calibration) solution through the flow chamber. Adjust the flow until the liquid is foam-free. The flow rate should be a minimum of 150 ml/ min and be stable.

Note:

A flow rate lower that 150 ml/min can be used for the calibration, but you must ensure that all measurements made after the calibration are made at exactly the same flow rate as is used for the calibration. To ensure accurate results it is recommended to use a model 32311 Flow Meter as described in “Model 32311 Flow Meter” on page 41.

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.

ORBISPHERE Operator Manual