Performing a Span Calibration

To perform a span calibration, select “Span Hydrogen”, attach the Span Gas to the Calibration Gas Inlet port, and begin the flow of gas at 1.5 to 2.0 SCFH.  The Target Value should be set to the exact amount of Hydrogen that is in the Span Gas cylinder.  Then the same procedure should be followed as the Zero calibration, with the “Calibrate” button being pressed after the readings reach equilibrium.  After the Span Gas calibration is complete, turn off the flow of gas, disconnect the cylinder from the enclosure, and restore the valve on the side of the instrument to the “Sample Gas” position.  This will re-connect the sensor to the process gas stream.