John Perry Laboratory

The John Perry Laboratory (JPL) at St George’s Healthcare was set up in 1990, specifically for the calibration of radiation measuring instruments used in diagnostic radiology. It is the only purpose-built facility of its kind in the UK, providing a one-stop shop for repair and calibration.

JPL provides calibration maintenance and repair services for dosemeters and kVp dividers (non-invasive and invasive) used in diagnostic radiology. JPL has also added densitometers and sensitometers to the range of equipment that it can calibrate.

The laboratory also offers a broad range of other services, including x-ray transmission measurements for manufacturers or radiation protection materials such as lead, lead-backed plasterboard and lead rubber. The team can also carry out radio-opacity testing for manufacturers of such items as endotracheal tubes, catheters and other tubing used in diagnostic radiological procedures.

There are five laboratories, two of which are dedicated to dose meter calibration, and two of which are for kvP meter calibration and instrument repair checking. The fifth is an optics laboratory where the sensitometers and densitometers are calibrated.

The facility is the recognised European calibration and repair facility for Radcal.

JPL has recently been audited and formerly accredited to ISO 17025:2005. The facility is the only laboratory accredited for its particular type of work in the UK and one of very few in Europe. St George’s Healthcare is extremely proud of having achieved this distinction.

Facility summary

  • Purpose-designed laboratories, certificated to ISO 9002 (2001) and IEC.ISO 17025
  • Fast, accurate and reliable service
  • Traceable calibrations, carried out under conditions used in the field
  • X-ray beam qualities to meet customers’ needs
  • European calibration and repair agent for several manufacturers
  • One-stop calibration and repair service
  • Pick up and return of instruments available


For further information or a quotation please contact JPL manager Mr Mehboob Rathod on 020 8725 1498 or e-mail