O-1PST (Wi-Fi) Maintenance

Proper maintenance is essential to ensuring the long-term performance, accuracy, and reliability of the Open Air ( O-1PST) monitor. While the monitor is designed for durability and minimal upkeep, regular care can prevent issues and extend its lifespan, ensuring consistent and accurate air quality readings.

This guide outlines best maintenance practices to keep the device operating optimally in urban outdoor conditions.

1. Maintenance Considerations

When deploying the Open Air (O-1PST), choosing a location that facilitates regular maintenance is important. Please refer to Chapter P4: Site & Monitor Selection Planning.

2. Cleaning the Monitor & Sensor

Cleaning the Open Air is typically not required as the device is designed for long-term operation with minimal maintenance. However, occasional cleaning can help ensure a longer lifespan and optimal performance, especially in environments with high dust or pollution levels.

2.1 Cleaning the Vent

The blue vent at the bottom of the monitor can collect dust and other particles over time. Cleaning facilitates proper airflow to the sensors. While it does not need frequent cleaning, removing accumulated debris can prevent obstructions and maintain accuracy.

Procedure:

• Use a soft brush or a can of compressed air to remove dust from the vent area gently. You do not need to open the monitor for this.
• Do not use water or cleaning agents directly on the vent to avoid damaging the sensors if the liquid enters the monitor.

2.2 Cleaning the PM Sensor (Only for Abnormal Readings)

Cleaning the PM sensor is not recommended unless the monitor shows abnormal readings (this will be highlighted on the dashboard by the automatic failure detection feature), such as a complete lack of readings, consistently unexpected values or erratic performance. If cleaning is necessary, follow the below instructions:

• Before opening the device, we recommend simply blowing compressed air through the vents of the device to see if this solves the issue. If it does not, the monitor may need to be disassembled using the steps below.

Procedure:

• Power Down the Monitor: Disconnect it from the power source before handling.
• Open the Housing Carefully: Unscrew the four screws located at the bottom of the device and remove the top (white part) of the case from the blue bottom.
• Locate and unplug the PM module. It is a large blue box with a barcode on it. Remove the cable from this sensor and the module from the monitor before cleaning. To remove the cable, gently pull it out of the PM module. You should not need to use too much force. Once the cable has been removed, you can pick up the sensor.
• Clean Gently: Use a clean, soft brush or compressed air to remove dust from the PM sensor. Do not use liquids.
• Reassemble the monitor: Replace the sensor back in the case, plug the cable back in, and reassemble the monitor with the four screws.

Regular dismantling is not necessary and is only suggested for troubleshooting abnormal sensor behaviour. We do not recommend dismantling the PM module. If it’s visibly dirty or doesn’t work even after being cleaned, a replacement module should be used.

The non-PM modules in the Open Air should not require cleaning, but you can gently dust these down when opening the monitor if you would like to clean the device completely.

3. Software & Hardware Maintenance

The Open Air is regularly supported with both software and hardware updates. Software updates for the AirGradient dashboard do not require any action on your behalf, and the dashboard will automatically fetch the latest version when you access it.

Firmware updates for the device itself are OTA (over-the-air) and should also not require any actions on your behalf. As long as the monitor is connected to WiFi (for the O-1PST), it will automatically receive and install updates when we release them. These updates contain new features and bug fixes, so we always recommend keeping the monitors up to date.

If the monitor is disconnected, it will not receive updates, and these will need to be manually installed. Furthermore, if, for some reason, the monitor does not receive OTA updates, it will need to be manually updated. You can do this via this page on our website.

4. Power Supply & WiFi Connection

If an Open Air (O-1PST) monitor does not report data to the dashboard at all, it is likely a power supply or connectivity issue.

The Open Air (O-1PST) includes a 4m USB cable and can be powered by a 5-volt standard USB adapter. If readings are intermittent, we recommend trying a different adapter, as some don’t provide adequate power. If the issue persists, it could be related to connectivity.

• Troubleshooting the Power Supply:
  • Is the USB cable properly inserted at both ends, and is the cable safe from being dislodged due to high winds and other external factors?
  • Do other monitors exhibit the same issues when using the same cable and adapter? If so, we recommend trying a different adapter.
  • If neither of the above steps work, we recommend trying to update the firmware on the monitor via this page. If the device still won’t turn on, please reach out to our customer support team as there may be a hardware fault.
• Troubleshooting your Connection:
  • If the device is on (there is a flashing blue light on the bottom), but it won’t connect to your network, or you can’t see any information on the dashboard, please first ensure the WiFi strength is adequate. We recommend a WiFi strength of -30 to -80db. To check the WiFi strength, you can use an app on your smartphone. If the strength is low (-80 or higher*), this is likely the cause of your connectivity issues).
  • If the strength of your connection is not an issue, please update the firmware on the monitor via this page. When prompted, tick the box to erase the device. You will then need to connect the device to your WiFi network again, ensuring that the ‘Prevent connection to AirGradient servers’ tickbox is NOT ticked.
  • If this does not work, please reach out to our customer support team.

* When testing WiFi signal strength, the lower the number the better. -30dBm to -50dBm is considered excellent signal strength, and anything lower than -75dBm may cause issues.

5. Replacing Components

Nearly every component in the AirGradient Open Air can be individually replaced. Here are the components:

1. Mainboard (the main PCB (Printed Circuit Board) of the device with the USB port and connectors to the sensors).
2. PMS5003T particulate matter sensor (a large, blue box that is connected to the mainboard). This is the most likely component to need replacement as it has moving parts (a fan) inside.
3. SenseAir S8 CO₂ sensor (a sensor that sits next to the PMS5003T and is mounted on its own board. It is connected to the mainboard via a ribbon cable).
4. SGP40 VOC sensor (a small sensor that sits next to the USB port of the device).

Please refer to the images below for information on the placement of each component. Each of these can be purchased separately on the AirGradient store.

Before attempting to replace any components yourself, please keep the following in mind:
Always disconnect the monitor from its power source before opening the enclosure or replacing any components.

If you are uncomfortable with any aspect of the replacement process, contact AirGradient customer support for assistance.

Any of these components can be removed and replaced if there is an issue. Replacement is as easy as unscrewing the faulty component and replacing the new part in the same way. However, there are a few considerations to keep in mind:

• When replacing components (or cleaning them), ensure you have a clean area to do so. It’s very easy to lose small parts like screws, and having a clean desk top or other surface to work on will prevent you from losing important parts.
• Ensure you work in a dry environment. If the components get wet or damp, they may cease to function.
• Some components, like the ribbon cables (for the PM and CO₂ sensor) and the SGP40 VOC sensor are easy to damage if too much force is applied. Please be gentle when replacing these parts.
• After replacing a component, we recommend plugging the device in and checking that all sensors are functioning before deploying the device again.

6. Frequently Asked Questions (FAQs)

How often should I perform monitor maintenance?

There is no rule for this, as it largely depends on where the monitor is mounted and the conditions it is exposed to. However, we recommend checking the monitor every six months or when you notice abnormalities in the data. It’s also important to check the monitor after extreme weather (high winds, torrential rain, etc).

I have no experience with electronics, can I replace the components myself?

Yes! Replacing the components in the AirGradient Open Air is designed to be straightforward and you don’t need any experience to replace the components. If you are worried, please feel free to reach out to our customer support team for step-by-step assistance.

Why are my sensors not sending any data?

If your monitor is still online (you can still view up-to-date information on the dashboard), but some sensors are not showing any values, it’s likely that the sensor has died. If this is the case, we recommend first trying to unplug the sensor (the sensor itself, not the monitor) and then plugging it back in. If there is still no data from the sensor, a replacement is likely needed.

What can I do if I keep running into maintenance issues?

If you’re regularly running into issues, the placement of the monitor is likely an issue. The more extreme conditions the monitor is exposed to, the more likely it is to encounter issues. If this is the case, we recommend trying to move the monitor to a better (more sheltered) location if possible.

Developed by AirGradient in Collaboration with the UNDP Global Centre Singapore CC-BY-SA