v1.5

Minor Versionm

by Geoff Henshaw

Calibration - Gas zero

Written By: Margaret Grattan (and 2 other contributors)
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Introduction

Under some circumstances, sensors may temporarily exhibit a baseline reading higher than zero due to insufficient warm-up, or cross-sensitivity to other gases. In this case it is worthwhile checking against a standard zero air source.

Please allow 3 minutes for sensor warmup, after turning the instrument on and after swapping sensor heads.

  1. The calibration accessory has barbed fittings that are intended to fit with 1/8” ID tubing.

    • The calibration accessory has barbed fittings that are intended to fit with 1/8” ID tubing.

    • Care should be taken in selecting a tubing material that is appropriate for the type of gas that you will be using to calibrate the sensor head.

    • PVDF tubing is appropriate for most gases but the tubing's datasheet should be consulted for a full list.

    • Either side of the calibration accessory can be designated the inlet or the outlet.

    • Not all gas that enters through the inlet exits through the calibration accessory outlet; be advised that some gas exits through the sensor head exhaust. Depending on your calibration gas of choice and concentration levels, you may need to perform this calibration under a fume hood.

  2. Make sure the valve on your flow gas regulator is fully off.

    • Make sure the valve on your flow gas regulator is fully off.

    • Screw the gas regulator onto your gas cylinder. When the regulator is correctly fitted, the pressure indicator will show the cylinder pressure.

    • Always point the cylinder and regulator away from yourself and others when attaching or removing a pressure regulator.

    • Secure the cylinder so it can't be knocked over while the regulator is attached.

  3. Connect tubing to gas source and ventilation.

    • Connect tubing to gas source and ventilation.

    • Either side of the calibration accessory can be designated the inlet or the outlet

  4. Attach the sensor head to Ranger

    • Attach the sensor head to Ranger

    • Turn Ranger On

    • Attach the calibration accessory to the sensor head

  5. Check the cylinder pressure to ensure there's enough gas to perform the calibration (10% of full pressure should be enough).

    • Check the cylinder pressure to ensure there's enough gas to perform the calibration (10% of full pressure should be enough).

    • Gently turn the regulator valve anticlockwise and flow the target gas at >1L/min until the reading stabilizes (about 10 minutes).

  6. Wait for the gas reading to stabilize on the display of the Ranger

    • Wait for the gas reading to stabilize on the display of the Ranger

  7. Flow Zero air until the reading stabilizes (approx, 10 minutes). Press and hold the LEFT arrow key to enter the Settings menu. Navigate to Settings > Calibrate Select ‘Re-zero the sensor...’

    • Flow Zero air until the reading stabilizes (approx, 10 minutes).

    • Press and hold the LEFT arrow key to enter the Settings menu. Navigate to Settings > Calibrate

    • Select ‘Re-zero the sensor...’

    • Press OK to confirm.

    • Please wait for the ‘Preparing for calibration’ and ‘Calibration in progress’ screens.

    • Upon successful calibration, the instrument will display a ‘Calibration Complete’ screen.

Conclusion

For further support, contact Aeroqual Support.

One other person completed this guide.

Author

with 2 other contributors

Margaret Grattan

Member since: 03/09/2022

13 Guides authored