Sensor calibration

Aeroqual handheld and fixed sensors can be calibrated in the following ways:

• Factory calibration – Type 1 and Type 2 gas sensors, as well as the particulate matter sensors
• Field calibration – Type 1 gas sensors (except ammonia and perchlorethylene)
• Replacement – All sensors

For more information on sensor technology, which includes images, you may refer to the following page: Sensor technology

If you’re able to field calibrate your sensor head you may never need to send it to us for calibration. However if you want to be 100% sure of the calibration, an annual factory calibration complete with certificate provides ultimate peace of mind.

Ozone sensor heads are hard to calibrate in the field so we recommend sending these for factory calibration once every year. Below is an example of a calibration certificate that is shipped with your calibrated sensor head.

To organise a factory calibration or request a quote, contact Technical Support. Note: You only need to send the sensor head for factory calibration (note the monitor base).

Series 300 and 500 handheld monitors can be used to zero and span calibrate Type 1 gas sensor heads, except ammonia and perchlorethylene. Ranger monitors can be used to span calibrate all gas and PM sensor heads. The Series 200 monitor can only be used for a zero calibration.

For field calibration you need to buy the calibration accessory (part AS R42 for Series 300 and Series 500; part RGR CALKIT for Ranger), tubing, gas regulator and cylinders.

How often you field calibrate your sensor head depends on the level of rigour needed in your measurement application. Researchers and industrial hygienists may calibrate before every measurement they take. But for most people, regular calibration is enough to ensure good results. By regular, we mean once or twice per year.

In between calibrations, particularly when the monitor is being used for health and safety purposes, you can perform a bump test to see how the sensor is responding.

Field calibration of ozone

There’s an important difference between ozone and other types of gases. Ozone can’t be stored in bottles. Instead ozone must be generated at source using an ozone generator.

A zero calibration can be done using a zero air bottle, but for a span calibration you must be able to generate ozone. If you don’t have an ozone generator/calibrator, we recommend sending ozone sensors for factory calibration once every year. Contact Technical Support.

As the ozone sensor in the SM70 can’t be calibrated, you need to replace the entire sensor board once a year, or sooner if you suspect it isn’t working properly.

The SM50 sensor board is factory calibrated and designed as a single use sensor so it also needs to be replaced when calibration is due.

All replacement sensor boards come with a factory calibration certificate.

Sensor heads have a finite life due to environmental exposure, chemical life and oxidation.

To ensure continuous uninterrupted operation, we recommend you replace sensor heads every two years or when the ‘sensor aging’ or ‘sensor failure’ diagnostics appear.

Higher exposure levels or harsh environments can significantly reduce a sensor head’s life expectancy.

Note: Sensor heads can degrade even when unused and in storage.