To understand why it's important to calibrate your Clarity devices, please refer to What is calibration and why is it important?
Assessing Performance through long-term Collocation
Whether you performed a Custom Collocation-Based Calibration or you are relying on pre-applied Global Calibrations, your network of devices may need to be recalibrated or replaced over time.
The best way to assess if a recalibration or device replacement is needed is to have a on-going collocation with a maintained reference monitor near your deployment region. Aside from using the site for initial calibration, the site will also help track changes in performance of the Clarity Node-S as compared to the reference monitor over time.
If the reference site of the collocation is publicly available, you will be able to compare the performance over time in the Clarity Dashboard. Please refer to Compare your collocated Clarity device to a reference monitor.
A significant change in performance at this site can help start the discussion around if a recalibration or device replacement is needed, depending on the needs of the project.
Possible Reasons for a Recalibration
Both pre-applied Global Calibrations and Custom Collocation-Based Calibrations aim at capturing as much variability in environmental conditions and pollutant profiles as possible. However, devices may need recalibration for a few reasons:
- Exposure to extreme environmental conditions: The more environmental conditions differ from calibration conditions, the worse the sensor will perform. This is especially true of electrochemical sensors such as the one used to measure NO₂ in the Clarity Node-S.
- Exposure to unusual pollutant composition: The more pollutant composition differs from calibration conditions, the worse the sensor will perform. This is particularly relevant to particulate matter as pollutant source could change over the year (e.g., wood burning in the winter, smoke from biomass burning, wildfire smoke).
- Sensor drift over time: As sensors age, there will be some drift.
Because calibration and when to recalibrate is a on-going area of work at Clarity and within the broader indicative sensor space, please reach out to Support team and we're happy to discuss.
Possible Reasons for a Device Replacement
Clarity devices are engineered to function reliably in harsh conditions and are expected to last over three years. However, under certain circumstances, replacements may be necessary:
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Hardware Failures: Key components of the Node-S might malfunction before reaching their expected lifespan. Common issues include problems with the solar panel and battery system or the wireless communication system, though these are infrequent.
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Sensor Failures: Sensor components, while generally durable, can fail prematurely. For the particulate matter sensor, blockages in the optical path by elements like spiderwebs or pollen are typical issues. The NO2 sensor might experience electrolyte leakage due to rapid changes in temperature and humidity.
To ensure continuous and accurate operation, regularly check your devices' operational status on the Dashboard. Should you notice any potential issues or require a device replacement, do not hesitate to contact the Support team for assistance.