Overview

 

BEFORE YOU BEGIN:

 

Never perform a span calibration without first performing a zero calibration.

 

The Zero calibration should be performed with a gas that contains no hydrogen (0% H2).  Common gases used include nitrogen, argon, or ammonia. The concentration of the Span calibration gas should closely resemble the gas that is being measured. The span gas should contain a minimum %H₂ that the sensor could be exposed to during normal operations.  For example, if the sensor might see up to 75% H₂, the span gas should contain at least 75% H₂ in its chemistry.

 

NOTE: Since the accuracy of the calibration gas directly influences the resulting accuracy of the instrument, the highest possible accuracy grade should be obtained. Some gas suppliers refer to this as a “Certified Primary Standard”. The high degree of accuracy is not required to obtain nominal values that exactly match the values shown above. The accuracy is required to know the exact composition of the gas in the cylinder. The actual composition will be shown on the bottle when it is delivered.

 

When flowing calibration gas into the analyzer, turn the pump off. The amount of flow from the gas cylinder should be approximately 1.5 cfh at no pressure. The gas cylinders will be under high pressure, so it is recommended that a two stage regulator with a low pressure secondary stage be used. It is good practice to begin the flow of gas before attaching the calibration gas to the instrument. This will prevent any high pressure bursts from entering the instrument.

 

Calibration gases can be obtained from Super Systems, however they can also be obtained from any supplier of custom gases.