$6,887.00Add to order

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.

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 under two hours. At the end of each run, the detector prints out a complete report.

The RAD7 comes complete with all of these components and accessories:

  • RADLINK Remote Control Software
  • Wireless Infrared Printer, Battery Charger, rechargeable batteries & 6 rolls paper
  • External 12V Power Adaptor
  • 2 sets Velcro Tabs
  • 4 Drying Tubes
  • Gas Drying Unit
  • 5 lb Indicating Desiccant
  • 1 Dust Filter & 6 Inlet Filters
  • Vinyl Tubing
  • USB to Serial adapter cable
  • CAPTURE data acquisition and analysis software

The included accessories are sufficient for the measurement of radon and thoron in air. Additional, optional accessories are available for the measurement of radon in soil gas and water, for the measurement of the emission of radon from surfaces, objects and bulk materials, and for other specialised applications. See the Products Overview page for details.

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 under two hours.
  • 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.
  • The instrument 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 9.6 pounds (4.35 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 infrared data link for on-the-spot printouts.
  • Available with a wide range of optional accessories for measuring radon in water and below ground.
  • Versatile connectivity with an RS-232 port and USB adaptor
  • Includes CAPTURE software for data retrieval and analysis. Full Windows and macOS compatibility.
  • Includes rechargeable batteries and extensive documentation.


RAD7 electronic radon detector

DURRIDGE RAD7 with optional bluetooth adaptor

RAD7 with optional bluetooth adaptor

DURRIDGE RAD7 components and accessories

The RAD7 comes with all of these components and accessories.

DURRIDGE RAD7 Standard Setup Diagram
RAD7 Standard Setup Diagram

Alpha Energy Spectrum
Alpha Energy Spectrum

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 choose a 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.

RAD7 Software

CAPTURE Software for Macintosh OSX and Windows

Getting Started: 1-Day Test with the RAD7

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
  • NORMAL  High sensitivity radon measurement
  • AUTO  Automatic switch from SNIFF to NORMAL after three hours run
  • THORON  Radon and thoron measured simultaneously and independently
  • GRAB  Analysis of air “grabbed” from a discrete sample
  • WAT  Automatic analysis of water samples with optional RAD H2O accessory
  • Radon in air with Sniff protocol for quick, spot reading
  • Thoron in air 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 optional RAD H2O and Big Bottle System accessories
  • Continuous radon in water with optional RAD AQUA and Radon-in-Water Probe accessories
  • Radon in soil gas with optional Soil Gas Probe and DRYSTIK accessories
  • Radon emission from soil and hard surfaces with optional Surface Emission Chamber accessory
  • Bulk radon emission from bulk materials and objects with optional Bulk Emission Chamber accessory
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 800 mL/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
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
Connectivity 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 0.1 – 20,000 pCi/L (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 7 through 10, and macOS
  • Automatic RAD7 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 with optional RAD H2O, RAD AQUA, and Water Probe accessories
  • Automatic combination of data from multiple RAD7s
RAD7 Dimensions 11.5″ x 8.5″ x 11″ (29.5 cm x 21.5 cm x 27.9 cm)
RAD7 Weight 9.6 pounds (4.35 kg)
Shipping Dimensions 17″ x 17″ x 17″ (43 cm x 43 cm x 43 cm)
Shipping Weight 33 pounds (15 kg)
LCD Display Output 2 line x 16 character alpha-numeric display
Case Material High density polyethylene
Infrared Printer Omniprint OM1000 Wireless Infrared Printer included
Power Supply 11-15V DC (12V nominal) @ 1.25A, center pin positive, or included internal EnerSys sealed lead acid rechargeable battery pack (6V nominal, 30Wh, 5Ah) See RAD7 Battery Material Safety Data Sheet (PDF)
Battery Longevity 24 hours in SNIFF mode; 72 hours in Monitor mode

RAD7 Manual (PDF)
RAD7 Specifications (PDF)
RAD7 Battery MSDS (PDF)

Expendable RAD7 Supplies
5 lb Indicating Desiccant

$67.00Add to order

25 lb Indicating Desiccant (8 mesh)

$286.00Add to order

25 lb Indicating Desiccant (10-20 mesh)

$270.00Add to order

RAD7 Printer Paper Rolls (x6)

$15.00Add to order

Additional RAD7 Supplies
Included with RAD7, but also sold separately:
Wireless Infrared Printer

$198.00Add to order

Laboratory Drying Unit

$86.00Add to order

Small Drying Tubes (x4)

$47.00Add to order

Inlet Filter Pack (x6)

$28.00Add to order

Dust Filter (x1)

$6.00Add to order

RAD7 Tubing Set

$38.00Add to order

USB to Serial Adapter Cable

$52.00Add to order