Durridge Company, Inc. services

The EPA recommends, and we agree, that continuous radon monitors be calibrated at least every year. RAD7 calibration requires four to five working days from the receipt of the instrument. As a preliminary to recalibration, we inspect and test every RAD7. If additional service is required, this may delay the return of the instrument.

The RAD7 is able to measure both radon (222-Rn) and thoron (220-Rn) concentrations simultaneously and independently. The standard radon calibration is performed with a precision of better than 1% and we guarantee the RAD7 absolute accuracy for radon to be better than 5%. However thoron has a very short half life (about one minute) so that the concentration in the air will change during sample acquisition. For every minute the sample gas is in transit from the sampling point to the measurement chamber, the concentration of thoron in the sample will drop by half.

If you discover that your RAD7 is malfunctioning, we recommend that you first call DURRIDGE and talk to a technician. A surprising number of minor `disasters` can be avoided by long-distance consultation.The next step, if consultation fails, is usually to send your instrument in for evaluation and repair. Please send any documentation of the problem that you might have (notes, printouts, etc.) and a short note describing the problem. Be sure that you put your name and telephone number on the note. Within 48 hours of our receipt of the instrument, we will call you to give a diagnosis.

Whenever you send your RAD7 in for repair or calibration, you have the option of having the latest available software installed. Most RAD7`s can be upgraded to the latest hardware configuration as well. You will be informed periodically of whatever new features are available for your RAD7. Please advise if you want to have an upgrade made. We intend to keep our RAD7 customers happy by keeping their instruments up-to-date and state-of-the-art.