How to Create a Sensor Lending Program

Community Projects
1

Many groups in our community buy large numbers of sensors with the intention of lending them out to other parties. We encourage this, as it is a great way to widen air quality monitoring networks. This guide is meant to assist you in running and maintaining a well-organized sensor lending program. There are a few things that you will want to keep in mind as you start and maintain your program.

NOTE: Please read the entire document before starting your program.

Registration

Before diving into a program’s meat and bones, it is important for you to have a good grasp of how device registration works. This will likely be your largest barrier when creating a sensor lending program.

While you are welcome to register all of the devices yourself, we typically see organizations allow the sensor hosts to register the devices. They will need some information from you to do so.

  1. To register a device, sensor hosts will need two things:

    • Device ID: A sensor’s device ID is physically printed on a label on PurpleAir devices. This is also the device’s MAC address, with leading zeros omitted.

    • Associated Email: Devices are automatically associated with the email used to purchase them. However, we can associate new email addresses upon request (which you can do by sending an email to contact@purpleair.com).

  2. If sensor hosts register the devices, they do gain the capability to set a number of things. As such, there are a few situations you’ll want to keep in mind:

    • Sensor Name: Sensor hosts will be able to set a sensor’s name during registration. This name will appear on the map. If you want your sensors to be identifiable on the map as part of your program, you will need to provide some sort of required naming scheme to the hosts.

    • Visibility: Sensor hosts can register a device as Public or Private, which affects its visibility on the map and the accessibility of its data to outside parties, such as researchers. If a device is registered as public, it will be viewable at map.purpleair.com. By default, private sensors are not viewable on the map. However, sensor lenders and owners are able to view their private sensors on the map. More information is available in this community article. You may want to provide specific instructions to sensor hosts if sensor visibility and data availability are important to you.

    • Owner’s Email: Sensor hosts can set a device’s owner’s email. As per the community article linked above, this email can be used to log in to the map and view a private sensor.

When a device is registered, both the associated and owner’s emails included on the registration form will receive a registration confirmation email.

Getting Started

Before you give sensors out to anyone, there are a few things you will want to do to prepare. Please note that none of these steps are required, so only follow the ones you deem to be useful.

If you or your organization has not yet bought sensors, you’ll need to determine what model you’re interested in. For relevant information, check out Which Sensor to Choose.

  1. Create a spreadsheet to track sensors and other information. This will be useful later when you collect the relevant contact information from sensor hosts. At a baseline, things like names, phone numbers, emails, or addresses can be useful. At the very least, you should be able to contact the sensor hosts. This makes it easier to track where the sensors are deployed and reach out to the hosts if necessary. For various reasons, sensors can go offline, and you may wish to have a method of contacting sensor hosts to get a sensor back online.

The previously mentioned registration confirmation email contains a link called Modify this registration that can be used to update sensor registration details.

  1. By default, sensors are associated with the email that was used on their original order. An associated email is required to register a device. Our recommendation is to create a generic email address, something like “PurpleAir@blank.com,” and have it associated with the sensors (which you can do by emailing contact@purpleair.com with the request). This will make things easier when positions change at your organization. You can then provide this generic address to sensor hosts for registration.

  2. Create a flier or guide for sensor hosts that assists them in the hosting process. Then, you can provide it to them when distributing sensors. Below are some considerations of what to include in the guide.

    • The generic associated email address suggested above.
    • Some basic setup information. Consider linking the PurpleAir Sensor Owner’s Guide.
    • Some sort of contact information that would allow sensor hosts to get in contact with you.
    • To facilitate sensor setup, you could provide a sensor’s Device ID here as well.
    • Any relevant information regarding the considerations in the registration section.
    • Any other requirements you would like sensor hosts to adhere to.

Maintaining Sensors and Retrieving Data

Depending on the purpose or intent of your program, you may need to access data from sensors you’ve lent out. To do this, you can use the information you receive in the registration confirmation email. There are two main ways of retrieving data from sensors: using the PurpleAir Map or through the PurpleAir API.

The PurpleAir Map

  • When a sensor has been connected to the internet and registered, it will be viewable on the PurpleAir map. We recommend exploring the map for a few minutes to see if its options meet your needs. Refer to the PurpleAir Map Guide for more information. You can also download data directly from the map.

  • If the map is sufficient for your needs, you will want to consider sensor visibility again. A sensor’s visibility on the map is affected by its public/private registration status.

If you want devices to be registered privately but still want to view them on the map, you can do so. The previously mentioned registration confirmation email contains a link that can be used to view a sensor on the map, whether it is public or private. Additionally, if you want to be able to view multiple private sensors at the same time on the map, we can create a special URL that will allow you to do so. If this is needed, put a request through to contact@purpleair.com.

The PurpleAir API

  • If the map does not meet your needs for data collection, you’ll need to retrieve data via the API. All data that PurpleAir has ever received is available through the API. This means that if a sensor has been online and connected to our systems, we are storing its data indefinitely, and you will be able to retrieve it. To get started with the API, please visit our API Landing Page.

Moving Sensors

It is possible that you will want to move a sensor from one location to another. This could happen for a number of reasons, one example being a transfer of sensor hosts. When moving a sensor, there are a couple of things to keep in mind.

  1. If you are going to move a sensor from one location to another physically, we ask that you contact us so that we can archive the device. We store all of the data that we ever receive from a device. However, we associate all of that data with a sensor’s registered location. Archival is a process that tells our system to stop associating data with that location. Then, when that sensor is next registered, all of its new data will be associated with the new location.

  2. If devices are going to be moved frequently for your lending program, and you determine that reaching out to us every time a device is to be moved may prove to be a hassle, we might recommend that you register the devices as private. This would mean that their data is not publicly available, and thus preserving location accuracy would not a concern.

Learn More

Data Download Tool
Q: How Do I Download Map Graph Data
Why Should I Put My Indoor Sensor On The Map

2 Likes
3

Thank you for sharing, this is really helpful. Can you please explain why you recommend letting sensor hosts register the devices?
I assumed that the central organiser would be best placed to register all of the sensors before lending them out, to make life easier for the hosts and to help with logistics. For example, ensuring a naming protocol was followed and being able to manage multiple sensors at once.

2 Likes
4

Hello Amelie, and welcome to the PurpleAir Community!

Great question! Many organizations have successfully handled sensor registration using the method you described, and it’s absolutely a viable approach. That said, we’ve found that in cases involving a large number of sensors—sometimes even hundreds—this method can become challenging to manage.

For this reason, we wrote the article to highlight how the registration process can be distributed among sensor hosts effectively, making it more manageable for some organizations.

Still, you make a great point that this acknowledgement of both approaches isn’t as clear as it should be in the article. I’ll bring it up with the team, and we’ll see if we can update the article to better describe this.

Let us know if you have any other questions—we’re here to help!

1 Like