The Testo 317-3 is an ambient carbon monoxide monitor built for gas engineers servicing or installing boilers and heating systems. It measures CO from 0 to 1999 ppm with 1 ppm resolution, giving accurate readings from trace ambient levels through to dangerous concentrations, with adjustable visual and audible alarms to suit the site.
There's no zero phase — the monitor is ready to use the moment it's switched on, with no warm-up delay between jobs. It runs for a rated 150 hours on 2 x AAA batteries, so it can be used across multiple sites without needing frequent battery changes.
Carbon monoxide is colourless and odourless, and can reach dangerous concentrations quickly, which is why a reliable monitor is considered essential equipment for gas engineers rather than optional. The kit includes a carrying case with belt clip so the monitor stays accessible throughout a job, along with headphones for hearing the alarm in loud boiler rooms, and a wrist strap to reduce the risk of dropping it on site.
If a reading indicates dangerous CO levels, the area should be evacuated immediately and the emergency services contacted before any remedial work is carried out.
No zero phase means the monitor is ready to use as soon as it's switched on, which matters when moving quickly between jobs. A 150-hour battery life from 2 x AAA batteries means it can go weeks between changes rather than needing regular charging, and the included headphones make sure the alarm is heard even in a loud boiler room. The 3-year sensor warranty covers the component most likely to need attention over time, giving confidence in the monitor's accuracy for years of regular use.
Order the Testo 317-3 CO Monitor online today.
| Brand | Testo |
|---|---|
| Model | Testo 317-3 |
| Product Type | Ambient CO Monitor / Detector |
| CO Measuring Range | 0 to +1999 ppm |
| CO Accuracy | ±1 digit ±10% (30–1999 ppm); ±3 ppm (0–29 ppm) |
| CO Resolution | 1 ppm |
| Alarm Type | Visual & Audible – Adjustable Thresholds |
| Zero Phase | Not Required – Instant Readiness on Switch-On |
| Operating Temperature | -5 to +45°C |
| Storage Temperature | -20 to +45°C |
| Battery | 2 x AAA Micro |
| Battery Life | 150 hours |
| CO Sensor Warranty | 3 Years |
| Product Warranty | 2 Years |
| Includes | Carrying Case with Belt Clip, Headphones, Wrist Strap, Sampler & Calibration Protocol |
| Suitable Applications | Gas Heating Servicing, Boiler Installation, Ambient CO Monitoring & Safety Checks |
