RAD7 Calibration

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.

DURRIDGE maintains a radon calibration facility that includes a controlled, standard source of radon gas. All RAD7 alignment and calibration is conducted at the DURRIDGE offices, as well as basic testing and quality assurance. We determine calibration factors by direct comparison to "master" RAD7s, which were themselves compared with EPA and DOE instruments, and which have participated in international inter-comparisons of radon instrumentation. The calibration accuracy is independently verified by direct determination of the radon chamber level from the calibrated activity and emission of the standard radon source. In addition, we regularly inter-compare with other radon chambers. We achieve a reproducibility of better than 2% with our standard RAD7 calibration. Overall calibration accuracy is better than ±5%.

Shipping Information

We recommend that you arrange for your RAD7 servicing ahead of time, to avoid possible delays. When sending your RAD7, please send the instrument only, without the accessorie, unless they are relevant to the problem.

Each RAD7 is originally shipped to in a plastic bag, packed in a box with "popcorn", and finally packed inside another box that also holds all the accessories. The inner box by itself is too small for the return trip, when you need a calibration or repair job. You will need to find a bigger box, with space for one inch packing all round the RAD7. A 14" cube box is fine. Pack the box well, with at least an inch of padding all around, and seal it carefully.

All return shipments to DURRIDGE must be prepaid, and unless you instruct us otherwise, we'll return it to you via the same shipping method you used to get it to us - from "slow boat" to "next day air" - freight collect.