The Duomo Carbon Monoxide Detector is a portable digital CO monitor with a dual display, showing the current CO reading and the maximum level recorded since power-on at the same time. That peak reading is useful in its own right — if CO was present in a space and has since dissipated, the maximum figure still shows what the peak exposure was, without needing to watch the display continuously.
It measures CO across a 0 to 999 ppm range with 1 ppm resolution, and offers eight adjustable alarm thresholds from 25 to 200 ppm to suit different applications. A low threshold around 25 ppm gives early warning on domestic boiler service calls, while the higher thresholds up to 200 ppm suit industrial or confined-space monitoring where more headroom is needed before an alarm triggers.
The audible alarm uses a Geiger-style pattern, increasing in frequency as CO concentration rises, giving a sense of severity even without looking at the display. The unit is ready to use within 15 seconds of switching on, and runs for a rated 250 hours on 3 x AAA batteries with the backlight off, or 35 hours with it on — notably longer than many comparable portable CO detectors. Fresh air correction settings (0, 100 and 500 ppm), auto power off and a low battery indicator round out the feature set, and it comes with a soft carry case and wrist strap.
Most CO detectors only show the current reading, so if concentration drops before you check the display, that information is lost. The Duomo's dual display keeps the peak reading visible alongside the current one, which is useful if CO has already started to clear by the time you notice it. Eight adjustable thresholds mean the same unit covers both low-threshold domestic checks and higher-threshold industrial monitoring, and at 250 hours on 3 x AAA batteries with the backlight off, its battery life comfortably outlasts many comparable portable CO detectors, including the Testo 317-3's 150-hour rating.
Order the Duomo Carbon Monoxide Detector online today.
| Brand | Duomo |
|---|---|
| Model | HHCO |
| Product Type | Portable Carbon Monoxide Detector |
| CO Measuring Range | 0 to +999 ppm |
| CO Accuracy | ±1 digit ±20% (0–100 ppm); ±15 ppm (100–500 ppm) |
| CO Resolution | 1 ppm |
| Alarm Thresholds | 25, 30, 35, 45, 50, 70, 100 & 200 ppm – Adjustable |
| Alarm Type | Geiger-Style Audible (Frequency Increases with CO Level) & Visual |
| Display | Dual Digital – Current & Maximum CO Level |
| Backlit Display | Yes |
| Startup Time | 15 Seconds |
| Fresh Air Correction | 0, 100 & 500 ppm |
| Auto Power Off | Yes |
| Low Battery Indicator | Yes |
| Battery | 3 x AAA Micro |
| Battery Life | 250 hours (Backlight Off) / 35 hours (Backlight On) |
| Warranty | 2 Years |
| Includes | Soft Carry Case & Wrist Strap |
| Suitable Applications | Gas Heating Servicing, Boiler Installation, Confined Spaces & Industrial CO Monitoring |
