Sensor Calibration

 

To ensure accurate readings, the gas sensor must be calibrated at the low end and high end of the measured gas composition range. SSi recommends calibration be performed at least once per year, or as needed.

 

Connect the gas to the “Cal Gas Inlet” on the side of the SGA enclosure and open the valve.  It is recommended to let everything (gas and SGA) sit for approximately thirty minutes to allow the temperature to achieve equilibrium. 

 

 

To perform a sensor calibration, make sure that the system is set up to flow both zero gas (with 0% of the gas the sensor is designed to detect) and span gas when needed. The gases should be “Certified Primary Standards” or equivalent accuracy. Then follow these steps.

  1. Note the percentages of the sensor gas in each gas source (zero and span).

  2. Ensure that the system is purged of any latent gas.

  3. Flow the zero gas. Wait two minutes, and then enter the target gas concentration in the “Enter gas concentration” field.

  4. Press “Calibrate”. A Calibration Timer will count down.

  5. Once the Calibration Timer has counted down, the zero value will be calibrated.

NOTE: The remaining steps for the span gas will be very similar to the steps performed for the zero gas calibration.

  1. Ensure that the system is purged of any latent gas.

  2. Flow the span gas. Wait two minutes, and then enter the target gas concentration in the “Enter gas concentration” field.

  3. Press “Calibrate”. A Calibration Timer will count down.

  4. Once the Calibration Timer has counted down, the span value will be calibrated.

 

Figure 9 - Sensor Calibration Page