Leaders in professional radon instrumentation and analysis solutions    


Big Bottle System

High Sensitivity Radon In Water Accessory for the RAD7


Note: The following photos and diagrams show the Big Bottle System with Aerator Cap Revision C, which is coming soon. For information on the currently available Revision B, see the Revision B version of the product manual.

The Big Bottle System is an accessory for the RAD7 that enables users to measure radon in 2.5L water samples with high sensitivity. The lower limit of detection is well below 1 pCi/L (40 Bq/m3) radon concentration in water. The upper operating limit is 10,000 pCi/L (400,000 Bq/m3). For ranges higher than that, the standard RAD H2O accessory is recommended.

The Big Bottle System consists of several components, including the Tubing Set, Support Stand, Elastic Clinching Strap, USB Temperature Logger, Hermetically Sealed Thermocouple, and two 2.5 L Glass Bottles. The tubing set includes a check valve, aerating stones, and aerator cap. A RAD7 is required, as is either a Laboratory Dryer or DRYSTIK.

The complete system (excluding the optional DRYSTIK), is portable and battery operated, and the measurement is moderately fast. Even for the lowest radon concentrations you can have an accurate reading of radon in the water within two hours of taking the sample.

The Big Bottle System gives results after 120 minutes of analysis, or less, with a sensitivity that far exceeds that of liquid scintillation methods. The method is simple and straightforward, and there are no harmful chemicals to use. Once the procedure becomes familiar and well understood it will produce accurate results with minimal effort.

Soda Bottle Coupler-Cap Accessory

For added convenience and versatility, the Big Bottle System can be used with standard soda bottles of any size from 500 ml to 2 liters. This configuration requires the Soda Bottle Coupler-Cap accessory, which is used with an aerator system similar to that used in the standard 2.5 Liter jug.

Larger bottles allow for greater precision and lower limits of detection. With a 500ml bottle, it is possible to measure comfortably down to below 5 pCi/L (200 Bq/m3). With a 2L bottle it becomes possible to measure down to 1 pCi/L (37 Bq/m3).

CAPTURE Software Integration

DURRIDGE's CAPTURE software makes it easy to download and analyze data recorded using the Big Bottle System. The program provides controls for identifying the specific experiment configuration, and it automatically calculates radon concentrations with respect to the the specified water temperature and volumes. The software is free to use and is available for download here.

Big Bottle System Physical Specifications

Glass Bottle System Shipping Dimensions

17" x 17" x 17" (43 cm x 43 cm x 43 cm)

Glass Bottle System Shipping Weight

11 pounds (5.0 kg)

Soda Bottle System Shipping Dimensions

14" x 14" x 14" (36 cm x 36 cm x 36 cm)

Soda Bottle System Shipping Weight

5 pounds (2.3 kg)

Retort Stand Shipping Dimensions

37" x 8" x 2" (94 cm x 20 cm x 5 cm)

Retort Stand Shipping Weight

6 pounds (2.7 kg)



Big Bottle System Manual (Aerator Cap Revision C, PDF)

Big Bottle System Manual (Aerator Cap Revision B, PDF)


Big Bottle System Configuration Photo

Big Bottle System Configuration Diagram

Big Bottle System Aeration Video

Featured Articles

Product Comparison: Radon In Water Accessories (HTML)

Related Accessories



Indoor Faucet Connector (HTML)


Price List (HTML)

Big Bottle System with Aerator and Temperature Data Logger

Soda Bottle Aerator Kit for the Big Bottle System

The Aerator Cap has undergone revisions to improve ease of use and reduce the risk of water entering the desiccant.


Products Accessories Services Software Support More
RAD7 Radon Detector
Big Bottle System
Water Probe
Soil Gas Probes
Range Extender
Emission Chambers
CO2 Logger
Cool Trap
Duty Cycle Controller
Indoor Faucet Connector
Natural Rock Sample
Relay Box
Serial Bluetooth Adaptor
USB to Serial Adaptor
Water Switch
RAD7 Calibration
Thoron Calibration
RAD7 Repair
Firmware Upgrades
Software Drivers
Product Manuals
Support Contacts
Video Tutorials
Research Papers
External Radon Links
Company Information
Customer Testimonials
Contact Us