GQ Electronics RadonScan-Plus

GQ's user guide covers three models together, the RadonScan, RadonScan-Plus and RadonPRO, and its January 2025 revision is described as revised for the RadonScan-Plus. It says the detectors use a high-sensitivity GQ Radon Gas Sensor: as radon passes through the sensor, it triggers an electrical signal that the processor registers. The sensor type and whether air reaches it by diffusion or a pump are not stated by the maker.

The specification table, shared by all three models, lists a range of 0.00 to 100 pCi/L (0.00 to 3700 Bq/m3), radon-222 as the gas registered, an alarm level settable from 0 to 99 pCi/L, a back-lit color LCD dot matrix display and 1 MB of flash memory for data storage. The only performance figure is a reproducibility of indication of 30%; GQ does not state an accuracy against a reference level, and no operating temperature or humidity range appears in the guide or on the store page.

GQ says the first background radon reading appears within about 5 minutes of powering on, and that radon data are collected continuously and passed to the processor every second. Its RadonScan-Plus store page says the unit logs data into internal memory every second. The main screen shows four averages, 1 Hour, 1 Day, 1 Week and Long-Term, and the guide's own advice is that readings vary with time and place, so averaging over a longer period gives the most accurate result. The averages are kept when the unit is turned off until you clear them with Reset Data.

What GQ says sets the Plus apart from the plain RadonScan is Wi-Fi. The guide says the RadonScan Plus and the RadonPro offer Wi-Fi, that the RadonPro and RadonScan-Plus can submit data online, and that you can view real-time data on iOS or Android devices, with free online data storage. To do that you create an account on GQ's site, register a radon detector there to get a user ID and counter ID, enter them in the unit's Server settings (the default website is www.gmcmap.com, and you can enter your own server instead), connect to your network, and run Test Connection, which returns "Successful" when data is sent correctly. A Period setting sets how often data is sent; the guide does not list its values.

The documents disagree on one point. The guide's own section on the GMCmap mobile app names only the RadonPRO model, while its overview and GQ's RadonScan-Plus store page describe a real-time app for the Plus, which the store page says you can download to a cellphone, with Wi-Fi that can be disabled or enabled. The store page also repeats a line about a radiation result in one minute; the guide lists radiation readings and the Geiger counter for the RadonPro only, and the RadonScan-Plus main display shows radon alone.

For alerts, the unit has a buzzer with an adjustable beep volume and front and rear LEDs. The guide lists the LED colors as green for normal readings, yellow for medium and red for high, and lets you choose which reading triggers the radon alarm. Pressing any key silences the beep until the reading drops below the threshold or the unit is powered off.