O-M-1PPSTON (Open Air Max) Maintenance

Proper maintenance is essential to ensuring the long-term performance, accuracy, and reliability of the Open Air Max ( O-M-1PPST-CE and O-M-1PPSTON-CE) 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 Max (O-M-1PPST-CE and O-M-1PPSTON-CE), choosing a location that facilitates regular maintenance is important. A well-thought-out placement supports accurate data collection and simplifies routine upkeep.

• Accessibility: Select a location that is easy to reach for periodic cleaning, sensor calibration, or component replacement. Ideally, the monitor should be easily unmounted in case sensors need replacement.
• Weather Protection: While the monitor is weather-resistant, deploying it in a partially sheltered area can reduce the impact of extreme conditions, making maintenance tasks easier and less frequent.
• Insects: Although it may not seem like it, insects entering Open Air monitors can happen. If these insects enter the sensors, they can cause inaccurate readings and other issues. If possible, don’t mount the device on surfaces like trees, where insects are more common.
• Cable Management: Ensure the power cable is routed securely and remains accessible for inspection or replacement without the need for disassembly or extensive effort. Keeping the cable off the ground is also recommended to prevent damage by animals or other factors.
• Safety: Choose a stable and secure mounting surface to minimize the risk of accidental dislodgement or damage, particularly in high-traffic or urban environments.
• Sunlight: For the Open Air Max, it is important that the monitor is placed in an area that receives at least a few hours of direct sunlight most days. If the monitor is placed in a shaded area, you may notice drop-outs due to a lack of power.

2. Cleaning the Monitor & Sensor

Cleaning the Open Air Max 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 grey 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.
• 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 as we have algorithms in place to detect such behaviour), such as a complete lack of readings, consistently unexpected values or erratic performance. If cleaning is necessary, follow the below instructions.

Before opening the monitor, we recommend first blowing compressed air through the vent at the bottom of the monitor. This may prevent or reduce the need to dissemble the device, which can be time-consuming. If this does not work, please follow 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. The Open Air Max has two particle modules, so you may want to remove and clean both.
• 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 Max should not require cleaning, but you can gently dust these down when opening the monitor if you would like to clean the device completely.

2.3 Cleaning the Solar Panel

The Open Air Max comes with a solar panel, and you might notice that the solar panel gets dirty over time. If this is the case, we recommend cleaning it with a tissue to remove the dust and other dirtiness on the panel itself. This isn’t vital, but the panel performance will drop as it becomes more dirty, so we recommend cleaning it if you begin to notice issues with the device’s power.

3. Software & Hardware Maintenance

The Open Air Max 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 a cellular network, 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 Max monitor does not report data to the dashboard at all, it is likely a power supply or connectivity issue. The Open Air Max is powered by a solar panel and has a cellular connection.

• Troubleshooting the Power Supply:
  • Ensure the solar panel is clean and free of obstructions that could prevent it from receiving sunlight. Clean the panel with a soft, dry cloth.
  • Ensure that the cable from the solar panel is properly plugged into the device.
  • Test if the device can be powered on via USB. Note that this will NOT charge the batteries, but it will allow you to identify if the device has an issue related to the solar panel or the device itself.
  • If the device is still not powering on, there may be an issue with the solar panel, or the internal battery. Contact customer support.
• Troubleshooting your Cellular Connection:
  • First, check if the device has power. If it does not, follow the power trouble shooting steps above.
  • If the device has power, but is not reporting data, ensure that the cellular connection is working in that area. This can usually be done by checking the signal strength on a smartphone or other cellular device.
  • 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, or if you are having cellular connection issues, please reach out to our customer support team.

5. Replacing Components

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

1. Mainboard (the main PCB 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. Cellular card (this contains the SIM card that can be changed)
4. Cellular antenna
5. Alphasense NO₂ module (this is only found on the O-M-1PPSTON model, not the O-M-1PPST model)
6. Alphasense O₃ module (this is only found on the O-M-1PPSTON model, not the O-M-1PPST model)
7. 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).
8. Battery cells (18650 batteries)
9. SGP40 VOC sensor

The O-M-1PPSTON-CE also houses an ozone and nitrogen dioxide sensor from Alphasense. Please note that these sensors need to be replaced every two years for the best performance.

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. Other Maintenance Considerations

Some components in the Open Air Max will need to be replaced over time. While there is no definite lifespan for these sensors, the longer they are left without replacement, the less accurate they become. Here are our recommended replacement cycles for the Open Air Max components:

Ozone and nitrogen dioxide sensors: these should be calibrated every six months and replaced around every two years. If they go longer than two years without replacement, they may become inaccurate.

PM sensor: The Plantower PMS5003 PM sensor does not need to be replaced on a regular schedule, but it should be replaced if issues begin to occur. To identify if a sensor needs replacement, please refer to O3: Maintaining Data Quality and Accuracy.

The other sensors in the Open Air Max have an expected lifespan of 10 or more years and should not need to be regularly replaced. This also goes for the batteries and solar panels. However, please note that, while the expected lifespan is 10 or more years, we only offer a one-year warranty.

It’s also possible that in some environments the lifespan of these components will be decreased.

7. 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