rad7  Radon monitor and sniffer

 Soilgas sampler / monitor

 Radon in water sampler / monitor




The DURRIDGE RAD7 is a truly versatile radon detector of mature and yet still state-of-the-art design. Its specifications match or exceed those of the most expensive radon measurement devices in the world. At the same time, it incorporates a number of exclusive features that are found in no other radon detector, regardless of price. Incredibly, the RAD7 is affordable

Download software for Rad7  (Windows/21,6MB)


Electronic radon detector with real-time monitoring and spectral analysis

The RAD7 is a sophisticated measuring instrument widely used in laboratories and research work around the globe, by radon testers, mitigators and home inspectors, in mines and deserts, on the ocean and up volcanoes, at extremes of temperature.

The RAD7 is also the simplest computer-driven electronic detector to use, with pre-programmed set-ups for common tasks. It's built to withstand everyday use in the field. A rugged, handsome case encloses the detector, which is self-contained and self-sufficient. The RAD7 comes complete, with a built-in air pump, rechargeable batteries, and a wireless infrared printer. The printer can be left in your office or your car, when desired, and the detector will collect data and store it for later printing or downloading to a PC.

The RAD7 is a Sniffer that uses the 3-minute alpha decay of a radon daughter, without interference from other radiations, and the instantaneous alpha decay of a thoron daughter. The RAD7 sniffs out entry points and radon gushers and recovers in minutes from high radon exposures. The RAD7 is also a Continuous Monitor that measures the EPA action level of 4 pCi/L, with 10% standard deviation, in one hour. At the end of each run, the detector prints out a complete report.



RAD7 Advantages

Precision and Performance

  • Fastest response and recovery times of any electronic monitor/sniffer on the market.
  • Measures EPA action level of 4 pCi/L in just one hour.
  • Recovers from radon highs in minutes - not hours.
  • Spectrum printout verifies correct operation of instrument in field.

Convenience and Ease of Use

  • All-in-one complete, compact, portable unit in handsome rugged carrying case.
  • Microcomputer directs you, step by step, so you can do what you want to do.
  • Programmed set-ups for often-used tests.
  • Audible radon and thoron counts lets you hear the hot spots.

Security and Flexibility

  • Tamper-proof key-lock command secures your RAD7 and assures uninterrupted testing.
  • Easily portable: The RAD7 weighs just 11 pounds (5 kg).
  • Displays, prints, and downloads radon data in your choice of units.
  • Immunity to build-up of 210pb.

Expandability and Value

  • Includes wireless printer and infra-red data link for on-the-spot printouts.
  • Available with a wide range of accessories for measuring radon in water and below ground.
  • Versatile connectivity with an RS-232 port and USB compatibility adaptor
  • Includes CAPTURE software for data retrieval and analysis. Full Macintosh and Windows compatibility.
  • Includes rechargeable batteries and extensive documentation.

Operating the RAD7

The RAD7 is remarkably easy to use. It's ready to operate from the moment you turn it on. The first thing you will see is the Setup Review, which displays the current settings. This allows you to check that your machine is set up the way you want it for your intended use.

Now you and your RAD7 are ready to go to work. The machine is preset for a 1- or 2-day test... or you can preset for your particular job that day. When you arrive on site, just push the buttons and the test runs automatically.

A RAD7 exclusive feature is "Auto" mode. This starts a test in Sniff mode for quick response, a base-line reading. After 3 hours it automatically switches to "Normal" mode for the remainder of the test, assuring statistical precision.

You can leave your RAD7 for a 24-hour, 48-hour or any-hour test, knowing that the measurements will be correct, thanks to the "Test Lock" command, which locks the machine until you return. The display shows "DURRIDGE RAD7", the test continues, and no amount of tampering - intentional or unintentional - can influence it.

action level of 4 pCi/L, with 10% standard deviation, in one hour. At the end of each run, the detector prints out a complete report.

USB and Bluetooth Connectivity

Stored RAD7 data may be downloaded to a computer using a USB or serial connection. DURRIDGE offers a dedicated RAD7 communications software package called CAPTURE, which automatically transfers RAD7 data to disk, displays radon graphs, and produces a variety of supplementary information. CAPTURE can also monitor a RAD7 in real time with its Chart Recorder. Learn more about CAPTURE here.

For situations where the RAD7 can not be directly connected to a computer, DURRIDGE offers the Parani SD1000 Serial to Bluetooth Adaptor. This adaptor offers a 100 meter wireless range, and it comes pre-configured for plug and play compatibility with the RAD7 and CAPTURE. An optional 16 hour battery allows the adaptor to be used even in the absence of a reliable power source.

RAD7 Specifications


Modes of Operation

SNIFF  Rapid response and rapid recovery radon measurement
THORON  Radon and thoron measured simultaneously and independently
NORMAL  High sensitivity
AUTO  Automatic switch from SNIFF to NORMAL after three hours run
GRAB  Analysis of grab samples
WAT Automatic analysis of water samples with RAD H2O accessory



Radon in air with Sniff protocol for quick, spot reading
Thoron protocol for searching for radon entry points
Radon in air 1-day, 2-day or weeks protocol for long term measurement
Radon in water batch samples with RAD H2O and Big Bottle RAD H2O
Continuous radon in water with RAD AQUA and Radon-in-Water Probe
Radon in soil gas with Soil Gas Probe and Active DRYSTIK
Radon emission from soil and hard surfaces with surface emission chamber
Bulk radon emission from bulk materials and objects

Data Storage


1,000 records, each with 23 fields of data
Log of printer output also stored

Sample Pumping


Built-in pump draws sample from chosen sampling point
Flow rate typically 800ml/min

Print Output


Short, medium or long format data printed after each cycle
Run summary printed at end of run, including averages and spectrum

PC Connectivity


RS232 serial port, full remote control implemented in CAPTURE Software.
Optional serial to Bluetooth adaptor for wireless PC connectivity.

Audio Output


GEIGER Tone beeps for radon and thoron counts
CHIME Chime only at the end of each cycle, otherwise silent
OFF No sound

Tamper Resistance


TEST LOCK command locks keypad to secure against tampering

Technical Specifications:

Principle of Operation

Electrostatic collection of alpha-emitters with spectral analysis
Passivated Ion-implanted Planar Silicon detector
SNIFF mode counts polonium-218 decays
NORMAL mode counts both polonium 218 and polonium 214 decays

Built-In Air Pump


Nominal 1 liter/minute flow rate
Inlet and outlet Luer connectors



RS-232 port up to 19,200 baud rate
USB adaptor is included with every RAD7

Measurement Accuracy


+/-5% absolute accuracy, 0% - 100% RH

Nominal Sensitivity


SNIFF mode, 0.25 cpm/(pCi/L), 0.0067 cpm/(Bq/m3)
NORMAL mode, 0.5 cpm/(pCi/L), 0.013 cpm/(Bq/m3)

Radon Concentration Range


0.01 - 20,000 pCi/L (0.4 - 750,000 Bq/m3)

Intrinsic Background


0.005 pCi/L (0.2 Bq/m3) or less, for the life of the instrument

Recovery Time


Residual activity in Sniff mode drops by factor of 1,000 in 30 minutes

Operating Ranges


Temperature: 32° - 113°F (0° - 45° C)
Humidity: 0% - 100%, non-condensing

Cycle Range


User controllable number of cycles, from 1 to 99 to unlimited, per run
User controllable cycle time, from 2 minutes to 24 hours

CAPTURE Software


Compatible with Microsoft Windows XP and 7, and Mac OS X
Automatic RAD7 location, connection and data download
Graphs radon, thoron, temperature and humidity over time
Automatic humidity correction
Statistical analysis tools track concentration averages and uncertainties
Chart Recorder mode provides real-time RAD7 status monitoring
Control RAD7 operations from computer via direct or remote connection
Automatic calculation and display of radon in water for RAD AQUA
Automatic combination of multiple RAD7 data

Physical Specifications:


11.5" x 8.5" x 11" (29.5 cm x 21.5 cm x 27.9 cm)



9.6 pounds (4.35 kg)

LCD Display Output


2 line x 16 character, alpha-numeric display

Case Material


High density polyethylene

Infrared Printer


Chamjin NewHandy 700 Wireless Infrared Printer included

Power Supply


11-15V DC (12V nominal) @ 1.25A, center pin positive, or internal rechargeable batteries (5Ah)
Optional AC input for non-EU customers

Battery Longevity


24 hours in SNIFF mode; 72 hours in Monitor mode