The RAD-S51 radon gas sensor is a compact static-diffusion instrument built for long-term, uninterrupted measurement of radon concentration in indoor air. Rather than sampling intermittently, it draws ambient air into a large collection chamber and counts alpha particles emitted by radon and its decay products, converting those counts into a radon gas concentration reading through a silicon detector and dedicated signal acquisition circuit. The result is a stable, continuous record of indoor radon levels that health, safety and environmental teams can act on.
Radon remains one of the most frequently underestimated indoor air hazards in workplaces, schools, basements and public buildings. Regulatory frameworks in many markets now expect documented, time-based radon records rather than one-off spot checks. The RAD-S51 responds to that expectation with a measurement range of 5 to 300000 Bq/m3, a detection limit of 5 Bq/m3, and a design that keeps working accurately through months of unattended operation.
| Indicator | Parameter |
|---|---|
| Detector | Silicon detector |
| Measurement object | Radon gas |
| Measurement range | 5 ~ 300000 Bq/m3 |
| Sensitive area | 100 mm2 (10 x 10 mm) |
| Sensitivity | 0.027 cph/[Bq/m3] or 0.982 cph/[pCi/L] |
| Detection limit | 5 Bq/m3 |
| Background count rate | ≤ 0.05 cph (nitrogen) |
| Uncertainty | ≤ 10% (K=2) after 120 hours at radon levels above 200 Bq/m3 |
| Measurement time | ≥ 60 min |
| Working voltage | 3.3V |
| Power consumption | ≤ 3.3 mW |
| Communication | 3.3V TTL level serial asynchronous output |
| Baud rate | 9600 bps |
| Working environment | -10 to +50 degC, ≤ 90% RH at +45 degC |
| Storage environment | -25 to +85 degC, ≤ 90% RH at +45 degC |
| Dimensions | 60 x 60 x 21 mm |
With a 3.3V supply, power draw of no more than 3.3 mW and a 3.3V TTL serial output at 9600 bps, the RAD-S51 connects directly to mainstream data loggers and embedded controllers without additional signal conditioning. Integrators can stream radon concentration values into existing monitoring platforms, trigger ventilation controls, or archive readings for compliance reporting. A measurement cycle of 60 minutes or longer supports both fast screening and long-duration studies on the same hardware, while the specified uncertainty performance gives project owners a defensible accuracy statement after a five-day stabilisation period.
Because the sensing principle relies on static diffusion, the module has no pumps, filters or moving parts to service. That simplicity keeps maintenance low in hard-to-reach installations such as crawl spaces, mine galleries and remote monitoring cabinets, and it keeps cost of ownership predictable across multi-year deployments.
The RAD-S51 radon gas sensor is available for volume orders with a supply capacity of up to 3000 pieces per month. Technical documentation, sensitivity figures and integration guidance are provided for OEM customers building radon monitors, environmental stations and building health systems. Buyers evaluating indoor radon detection hardware are invited to request samples, discuss parameter configuration for their target market, and confirm delivery schedules with the sales team.
