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Electronic radon detectors


We offer professional-grade meters for monitoring and measuring radon gas levels in indoor air in buildings, to activate ventilation systems, for integration into smart automation systems, and for measuring radon in water and soil:


  • Sarad Radon Scout Pro: Compact, high-precision radon meter with options for CO₂ measurement, atmospheric pressure, and ventilation system control.
  • Sarad Smart Sensor: Continuous radon monitoring, ventilation system activation, and integration in smart buildings.
  • Sarad RTM 1688-2: For fast and precise measurement of radon and thoron in air; accessories available for measuring radon in water and soil.
  • Airthings Pro: Very easy-to-use professional device for short- and long-term radon measurements in air.
  • Sarad Radon Scout: Industrial and academic reference device for long-term radon measurements in air.
  • Durridge RAD8: Successor to the Durridge RAD7, widely used in academic studies across various research fields worldwide.
  • E-PERM System: Complete system for measuring radon in air using passive detectors (electret ion chambers).


Sarad Radon Scout Professional (RS Pro)

The Radon Scout Professional (RS Pro) devices are high-precision professional instruments, compact in size, suitable for short- and long-term radon sampling as well as for personal dosimetry. The instrument is not affected by variations in temperature and humidity, external radiation, mechanical shocks, or vibrations. Two AAA batteries allow several months of autonomous operation.

The RS Pro is available in three versions: the standard version, a version with a built-in CO2 sensor, and a version with an atmospheric pressure sensor.

All data are stored in non-volatile memory and can be read via the USB interface.

Optionally, units can be supplied with a switch to activate a ventilation system when radon levels exceed a programmable threshold value.

Radon Scout Pro radon meter
Radon Scout Pro radon meter

Lucas cell technology enables high precision with short sampling times. The RS Pro can measure a concentration of 300 Bq/m3 in 1 hour with 15% precision, and achieve 8% precision in 1 day at a radon concentration of 50 Bq/m3.

The instrument includes a calibration certificate in compliance with DAkkS (German equivalent of ENAC). The calibration process meets the requirements of DIN EN ISO/IEC 17025:2018. (see example of the RS Pro calibration certificate)

The internal memory can store 16,383 data points. Recorded data include radon level in Bq/m3, exposure time, temperature, relative humidity, as well as CO2 level (optional) and atmospheric pressure (optional).

The RS Pro operates with 2 AAA batteries and can also be connected to an external power source via USB.


To request a quote for the Radon Scout Pro, please contact us:

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Sarad Smart Radon Sensor

The smart radon sensor offers very high sensitivity in a compact housing and is an ideal device for intelligent control of ventilation systems aimed at radon mitigation, including forced indoor ventilation and sub-slab depressurisation systems.

The instrument incorporates protection against variations in temperature and humidity, external radiation, mechanical shocks, and vibrations.

Sarad Smart Radon Sensor
Smart Radon Sensor

The Smart Radon Sensor provides several interfaces for integration into monitoring, ventilation, and automation systems. Below are the most common configurations and applications:

Sarad Smart Sensor connected via WiFi
Smart Sensor connected via WiFi to a PC with the free “ROOMS” software installed


Sarad Smart Sensor to activate ventilation system
Smart Sensor used to control forced ventilation activation


Sarad Smart Sensor and intelligent building automation system
Smart Sensor connected to an intelligent building automation system


Sarad Smart Sensor connected via Zigbee
Smart Sensor wireless long-distance connection via Zigbee interface


The RS-485 interface can operate with MODBUS RTU (industrial standard) or Sarad’s proprietary protocol. The analogue output allows easy connection of the Smart Radon Sensor to existing PLCs. An independent ventilation control system can be easily implemented using the alarm switch output. For easy installation, all connections are available via a screw terminal. If no data line is available, the optional integrated ZigBee wireless interface can be used for host system connection.

The wide-range power input accepts all common voltage supplies used in building automation. Measurement begins as soon as power is connected. Two AAA batteries are integrated to continue measurement in case of power interruptions. Temperature and humidity sensors are included by default, while CO2 measurement and barometric pressure are optional.



To request a quote for the Smart Radon Sensor, please contact us:

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Sarad RTM1688-2

Professional and very easy-to-use instrument, operated with a single button. Measures radon and thoron concentration simultaneously with very fast response, ideal for identifying radon entry points in buildings.

RTM 1688-2 radon meter
RTM 1688-2 radon meter

A versatile radon monitor, professional-grade but simple to operate, which does not require a desiccant tube to compensate for changes in relative humidity, unlike other meters of its class. In addition to measuring air radon concentration, the RTM1688-2 includes a sniffing mode to identify radon entry points, and optional accessories are available to measure radon in soil and water samples.

The instrument is equipped with temperature, humidity, and barometric pressure sensors.

Thanks to its integrated pump, soil gas sampling and radon-in-water measurement are possible. The instrument can connect directly to a modem for wireless data transmission or to a computer via USB. Radon Vision software is included for data analysis.

The power source of the RTM1688-2 can be an AC/DC adapter or an internal battery that provides up to 14 days of autonomous operation.

An integrated tilt detector warns if the instrument is moved from its original position during measurement.

Other optional accessories allow Internet data transmission, facilitating remote monitoring of radon levels.

Optional accessories for the RTM 1688-2

Soil probe

To measure radon concentration in soil, a probe is used that drills to a depth of one metre. The depth can be extended in 1-metre increments by adding additional probe sections. The Sarad accessory also allows measurement of soil permeability.

Sarad radon detector soil probe

"Radon Bubbler": measuring water samples

The "Radon Bubbler" accessory is used to measure radon concentration in water samples (500 ml). The Radon Bubbler provides a radon reading from the sample after 30 minutes.

See video on using the Radon Bubbler:

Sarad radon detector water accessory


For any additional information, please contact us.

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Airthings Pro

The Airthings Pro (formerly “Corentium Pro”) is a lightweight (only 300 g), portable, wireless continuous radon monitor that transfers data to a mobile device via Bluetooth and can also connect to a PC via USB.

Airthings Pro radon monitor
Airthings Pro (tripod not included)

The device is characterised by ease of use, portability, and long battery life from its 3 AA batteries (up to 1.5 years). It includes sensors for temperature, relative humidity, and barometric pressure. Its internal memory stores up to 5 years of data (1 sample per hour). It achieves 7% precision (standard deviation) after 24 hours of measurement, and 5% after 7 days.

The Airthings Pro (formerly Corentium Pro) samples indoor air through a passive diffusion chamber and uses alpha spectrometry to accurately calculate radon levels. Radon is detected using silicon photodiodes that count and measure the energy of alpha particles from the radon decay chain.


Mobile app

A mobile application is available to view, download, and analyse data on an iOS or Android device. It connects to the Airthings Pro via Bluetooth.

Airthings Pro app


PC software

Powerful software for viewing, downloading, and analysing data stored in the Airthings Pro memory is provided with the device on a USB drive.

Airthings Pro software


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Sarad Radon Scout / Radon Scout Plus

The Radon Scout devices are professional instruments used as academic and industrial references, widely deployed to measure indoor radon in buildings and underground spaces. There are two versions: the Radon Scout and the Radon Scout PLUS. The device connects to a PC to download and view data (software included); additionally, the PLUS version displays radon levels on an integrated screen.

Optionally, devices can be supplied with a wireless switch to activate a ventilation system when radon levels exceed a threshold value (set at 300 Bq/m3 in the Radon Scout and programmable in the Radon Scout PLUS).

Radon Scout Plus radon meter
Radon Scout PLUS radon meter

Radon Scout radon meter
Radon Scout radon meter

It can measure a concentration of 100 Bq/m3 in 2–3 hours with 17% precision. It updates data every hour (a 3-hour integration period can also be specified).

Internal memory can store 16,383 data points (PLUS version) or 672 data points (standard version). Recorded data include radon level in Bq/m3, exposure time, temperature, and relative humidity; additionally, the PLUS version incorporates an atmospheric pressure sensor.

The devices operate with 2 “D” batteries and have a connection for an external power supply. Thanks to continuous operation with external power, Radon Scouts are ideal for long-term measurements in workplaces, homes, public buildings, etc.

Other optional accessories allow Internet data transmission, enabling remote monitoring of radon levels.



To request a quote for the Radon Scout, please contact us:

Request quote



Durridge RAD8

The successor to the famous RAD7 continuous radon monitor—widely used in research studies on radon gas worldwide—the RAD8 includes several improvements, including IP67 resistance against water and dust even when the carrying/protection case is open, and expanded memory up to 16 GB, suitable for millions of measurements with full data and spectra.

Durridge RAD8 radon detector
Durridge RAD8 radon meter

The RAD8's high-resolution alpha spectrometry accurately measures the energies of alpha particles, allowing clear identification of the characteristic energy peaks of the radon and thoron decay chains.

This event-by-event species discrimination provides greater accuracy than other technologies, such as pulsed ion chambers and Lucas cells.

Thus, radon and thoron are measured independently and simultaneously, without interference. The long-lived decay product buildup background that affects other instruments does not influence RAD8 radon/thoron measurements.

This means that no matter how long the RAD8 is used, background will never interfere with measurements. Additionally, the RAD8 can recover from high radon concentrations within minutes instead of hours, saving time, reducing costs, and increasing productivity.

Optional accessories allow measurement of radon in water samples and soil.


Durridge RAD8 spectrum display
The RAD8 displays the alpha energies of the radon and thoron decay chains simultaneously on the built-in screen.



To request a quote for the RAD8, please contact us:

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E-PERM System

The E-PERM system uses reusable passive integrating devices known as electret ion chambers, which are placed at the measurement location for a specific period and then read using an electret voltage reader. Radon concentrations are calculated from the reduction in electret voltage using a laptop or PC.

E-PERM System
E-PERM electret chamber system

Electret ion chambers are low-cost devices, allowing simultaneous measurements at multiple locations. Short-term chambers are available (measurement periods from several days to several weeks, sensitivity of 300 Bq/m3-days with short-term electret) and long-term chambers (measurement periods from several weeks to several months, sensitivity of 75 Bq/m3-days with long-term electret). Thanks to their passive design, with no moving parts or electronic components, electret ion chambers are suitable for a wide range of locations and conditions. Accessories are also available for measuring radon in water.

The usual way to start with the E-PERM system is by acquiring a kit containing the following components: electret reader, reference electret set, 6 short-term chambers, 6 short-term electrets, and a set of anti-tamper cases. This kit is suitable for short-duration measurements (typically 7 days).

However, individual component combinations can also be supplied, including chambers and electrets suitable for long-term measurement periods.

E-PERM complete system

The complete system includes all components needed to perform indoor radon measurements over short measurement periods (typically 7 days, minimum 3 days). The system consists of 6 detectors (each composed of a chamber and an electret). Any number of chambers/electrets, short- or long-term, can be added either with the initial order or later. The basic system contains the following components:

  • 1 x SPER-1 electret reader
  • 1 x reference electret set
  • 6 x electret chambers (short-term)
  • 6 x electrets (short-term)
  • 3 x anti-tamper cases
  • 1 x nitrogen cleaning kit (regulator and hose)

E-PERM system

Chambers for long-term measurements

Long-term chambers are typically used for measurements of 60 to 90 days, in combination with a long-term electret. Reusable.

E-PERM long-term chamber


Chambers for short-term measurements (7–30 days)

Short-term chambers are typically used for 7–10 day measurements (with a short-term electret) or 30-day measurements (with a long-term electret). Reusable.

E-PERM short-term chamber


Electrets for long-term measurements

Suitable for 30-day measurements (with a short-term chamber) and 60–90 day measurements (with a long-term chamber). Delivered with an initial voltage of 700+ volts, suitable for several measurements.

E-PERM long-term electret


Electrets for short-term measurements

Suitable for shorter-term measurements (from a few days to several weeks) depending on the chamber used. Delivered with an initial voltage of 700+ volts, suitable for multiple measurements.

E-PERM short-term electret


To request a quote for the E-PERM system or its individual components, please contact us:

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