The uRADMonitor MODEL A3 is among the most capable multi-parameter air quality sensors currently available. Housed in a compact rugged enclosure, it integrates eight independent, high-quality digital sensors that monitor eleven air parameters: temperature, barometric pressure, relative humidity, volatile organic compounds (VOCs), formaldehyde, ozone, particulate matter (PM1, PM2.5, PM10), carbon dioxide, and noise level. Measurements are transmitted automatically through an abstracted communication layer (supporting Wi-Fi, Ethernet, GSM, LoRaWAN, or serial interfaces) and are available in real time.

Now in its 10th hardware revision, the MODEL A3 is approaching a new production iteration scheduled for early 2026. Until then, it is useful to address a common practical question: how the MODEL A3 can be used outdoors, where it is exposed to environmental conditions.

The traditional solution for outdoor use

Before the dedicated Stevenson Shield became available, users and deployers of the uRADMonitor MODEL A3 relied on creative DIY solutions to protect the device for outdoor use.

As highlighted in this 2021 article, the A3’s aluminum enclosure was not waterproof, making direct exposure to rain, snow, or sun risky for the sensitive electronics and sensors. The key challenge was balancing robust weather protection with adequate airflow to ensure accurate environmental readings.

Common approaches included placing the A3 inside custom-modified enclosures:

• Plastic boxes: Affordable and lightweight, these were drilled with openings on the bottom or sides to allow air circulation while preventing direct water entry. Examples include deployments on traffic light poles in Iasi and municipal installations in Bucharest.
• Metallic containers: Used especially for GSM-equipped models, these required an external antenna extension cable to maintain signal strength, as metal could interfere.
• Bell-shaped or pole-mounted housings: Inspired by simpler designs (similar to the uRADMonitor SMOGGIE), these featured side and bottom vents, with cables oriented downward to avoid water ingress.

Installation tips emphasized mounting the unit 1–4 meters above ground on poles or structures, aligning the A3’s intake/exhaust ports with enclosure openings, and prioritizing larger vents for better ventilation. Warnings stressed avoiding unprotected exposure, as even brief water contact could damage the device.

These DIY methods proved effective for many global networks but required manual effort and experimentation. They paved the way for the later introduction of the purpose-built Stevenson Shield, which now offers a standardised, professional-grade solution:

Enhancing Outdoor Environmental Monitoring: The new Stevenson Shield

The uRADMonitor MODEL A3 is a versatile, compact multi-sensor device designed for real-time environmental monitoring. Since its launch in 2016, it has been widely deployed in homes, cities, universities, and research institutes worldwide, with around 800 units currently in operation. For outdoor applications, where exposure to elements like rain and snow poses a risk to the device’s sensitive electronics, the Stevenson Shield emerges as an essential accessory. Specifically engineered for the MODEL A3, this high-quality housing transforms the indoor-oriented aluminum enclosure into a robust outdoor solution. Its innovative design provides direct access to ambient air, ensuring accurate measurements without compromise, while fully protecting the unit from weather damage.

Key features of the Stevenson Shield include weatherproof protection against precipitation, easy attachment options using plastic straps or metal collars, and compatibility with the A3’s multi-parameter capabilities. Whether for personal use or large-scale deployments, this shield enables reliable, long-term outdoor monitoring, making the uRADMonitor MODEL A3 an even more powerful tool in environmental data collection.

The shield can be purchased separately as an accessory for the model A3. Future plans might include it with the model A3 as a bundle.