Clarity Node-S Siting Guide
Choosing where to put your devices is a balance of technical considerations and on-the-ground realities. There's no single checklist that fits every deployment, but this guide covers the key things to weigh. If you'd like help identifying the best sites for your project, email support@clarity.io.
1. Determine your project goals
The best locations follow from what you're trying to learn, so clarify your goals first. Ask:
- Do you want to measure the impact of a specific source?
- Are you concerned with air quality at specific sites, like schools?
- Do you want a general picture of air quality across a community?
How common goals shape siting:
| Project goal | Siting strategy |
|---|---|
| Assess the impact of a particular source | Place devices both up- and down-wind of the source, and where the exposed population is. |
| Understand exposure for sensitive groups (children, the elderly) | Place devices at daycare centers, schools, or nursing homes. |
| Assess a policy intervention | Place devices in areas affected by the change and areas without it; monitor before and after. |
| Get a general picture of community air quality | Disperse devices throughout the area, capturing a variety of site types. |
| Learn about air quality where there's no regulatory network | Deploy following guidelines similar to reference monitoring networks. |
Once you know your goals, identify candidate sites — and identify more than you'll need, since practical factors (security, permissions, power access) will rule some out.
2. Secure site permissions
If a candidate site is owned or operated by someone outside the project, reach out early — some sites require formal agreements. Useful things to discuss with the site owner:
- Site access — how the project team will reach the site if maintenance is ever needed (it's minimal, but plan for it).
- Installation — how devices will be secured to the site.
- Power — the Node-S runs independently on its solar panel and battery, so it needs no power from the site owner. It can be powered externally if needed. Note: if powered externally, the power cord connection must be weatherproofed.
3. Survey the site and pick a mounting spot
If you can, survey the site before deployment day. A survey helps you identify exactly where to mount the device, confirm you have the right tools and mounting accessories (see deploying your Node-S), and take photos or diagrams for later.
The Node can be secured to a pole, fence, or railing with zip ties or hose clamps, or wall-mounted. Note: you can't currently wall-mount a device that has a solar shield.
A good mounting location should:
- Be at least 6 meters (20 ft) from obvious pollution sources like an exhaust vent, generator, or outdoor grill.
- Have the air inlet/outlet facing down and unobstructed for good airflow — ideally more than 270° of free airflow around the inlet, and no less than 180°.
- Ideally be away from buildings for better airflow. If you must mount on a building, use the upwind side.
- Be mounted at about 3–5 m (10–16 ft) above street level to measure general population exposure (higher for more regional air quality).
- Be in a secure location, ideally behind a fence or away from heavy foot traffic.
- Get enough sunlight to charge the device if you're using the solar panel — check it's not shaded by buildings, trees, or other structures. The device and solar panel should face south (northern hemisphere) or north (southern hemisphere).
Note: At its default sampling frequency, the Node-S needs an average of 1 hour of sun per day. It doesn't have to be evenly spread (four hours one day counts the same as one hour over four days). A fully charged Node can run up to 30 days without any sun.
Other resources
- California Air Resources Board (CARB) siting criteria
- US EPA Air Sensor Guidebook
- Guide for Monitoring Air Quality in London
- European Union Air Quality Directives
- Guidebook for Developing a Community Monitoring Network (Imperial County)
What's next
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Still need a hand? Email us at support@clarity.io or create a support ticket, and our team will get back to you.