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.

Shipping Information

1. You can send us your RAD7 at any time to either one of our Calibration facilities (USA and UK), listed below (see important, specific instructions for each below).

2. We need the RAD7 in house for 10 days, so the total time a RAD7 will be away from your facility will be 10 days plus the time the RAD7 spends in transit. If additional service or repair is required, this may delay the return of the instrument.

3. When sending your RAD7, please send the instrument only, without the cables and accessories. Pack the instrument upright in a box with one-inch (2.2cm) padding all around. A 14x14x14in (or 36x36x36cm) box is suitable. Pack the box well, and seal it carefully. Please include your contact info with the package.

4. International customers must be very careful, to avoid substantial extra shipping charges and delays, both for shipping to the nearest calibration facility, and for its subsequent return.

5. Commercial Invoice check-list:

  • For your courier or freight forwarder, you will need to provide a Commercial Invoice.
  • Please write only in English on the commercial invoice.
  • Please use the following description for RAD7: "Used RAD7 Electronic Radon Detector".
  • Insured value US$2,490.
  • Please state on the invoice that the instrument is MADE IN USA and that it is being "returned to the manufacturer temporarily for repair and recalibration".
  • Please use the HS (Commodity) code 9030.10.00.
  • Please mark the box with the serial number of the RAD7 (as the RMA – Return Merchandise Authorization).
  • Please add the phone number of the Calibration facility you choose, in case the Customs Office wants to call us.
  • Next, you must ensure that your courier (i.e. UPS, FedEX) or freight forwarder will deliver the package to our door. The formal "INCOTERM" for this is "DDP", which means "Delivered Duty Paid."
  • We will not pay or be responsible for USA or UK import duties, or Customs clearance charges. Your shipper must be told this when you arrange your shipment.
  • It is important to make sure you prepare all the documentation you need to reimport the goods back into your country without being charged.
  • For the Return to you: unless you instruct us otherwise, we will return your RAD7 via the same shipping method you used to deliver it to us, Freight Collect. DURRIDGE can pay for the return shipment CPT ("Carriage Paid To") to you, but our cost will be invoiced to you before shipment.

If we can help further, please email us at

Specific info for SHIPPING TO OUR USA FACILITY (from outside the USA)

DURRIDGE Company, Inc.
524 Boston Road
Billerica, MA 01821-2812, USA
Phone: +1 (978) 667-9556
Fax: +1 (978) 667-9557

Declaration Form

  • There needs to be documentation proving that the instrument was previously imported into your country, otherwise you may be charged import duties when the instrument is returned to your country.
  • Please fill out the declaration form provided below. Attach the completed declaration form to the commercial invoice. If the invoice is scanned and submitted electronically, please scan the declaration form and submit it electronically as well.
  • Foreign Shippers Declaration of US Goods Returned (PDF)

    Specific info for SHIPPING TO OUR UK FACILITY

    Sheffield Technology Park
    Cooper Buildings
    Arundel Street
    Sheffield S1 2NS, UK
    Phone: +44 (0)114 221 2003

    For Customers inside the EU:
    No special paperwork is required for shipping within the EU Customs Union.

    For Customers Outside the EU:
    Our UK office has a special authorisation from the UK tax authority (HMRC) to "import RAD7s temporarily for calibration and repair", without them being assessed for UK import duty. So when sending your RAD7 to our UK office, please state on the commercial invoice that the instrument is being imported using our Inward Processing Authorisation reference IP/0920/142/18. Failure to do so may result in import duty being charged, for which you will be responsible.