Leaders in professional radon instrumentation and analysis solutions    


Duty Cycle Controller

Accessory for Soil Probe and DRYSTIK Model ADS-1


Monitoring soil gas in the long term, for geotechnical and earthquake studies, is likely to dilute the soil gas sample with fresh air diffused down from the surface. The DURRIDGE Duty Cycle Controller can control the 12V supply to an Active DRYSTIK Model ADS-1, with a duty cycle anywhere from 100% to less than 1%. This means that the average flow rate can be carefully controlled to eliminate dilution of the sample and enable soil gas sampling to continue indefinitely.


The DURRIDGE Duty Cycle Controller controls the on and off time of a DC voltage powered device, resulting in lower power usage, lower consumption of consumable resources, and, in the case of a device with a pump, lower average flow rate. The DURRIDGE Duty Cycle Controller accepts a continually-on supply voltage between 9-15 VDC and converts it to a modulated square wave signal.

The Duty Cycle Controller has an ON time in each cycle of 3 seconds. The OFF time in the cycle may be varied from zero to 1,000 seconds or fully off.

Side benefits to reducing the flow rate include reducing wear on the Active DRYSTIK Model ADS-1 pump and increasing the life of the desiccant.

The Duty Cycle Controller can also control the power to any other 12V device, such as a sampling pump, whose current draw is not more than 1A. Thus a sampling pump may be set, by the Duty Cycle Controller, to pump for three seconds once every minute.


Duty Cycle Controller User's Manual (PDF)

Related Products

DRYSTIK Model ADS-1 Discontinued (HTML)

Soil Gas Probes (HTML)


Price List (HTML)



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