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Instrument calibration service

The Radiation Physics and Protection Service (RRPPS) offer a high quality calibration and repair service for a wide range of diagnostic X-ray and radiation protection instrumentation. Experienced and knowledgeable staff can provide standard calibrations, or calibrations where special conditions apply.

The instrument calibration service is used by customers including:

  • Medical equipment manufacturers
  • NHS medical physics departments
  • Specialist calibration companies

Why choose RRPPS to calibrate your instruments?

  • Our experience in radiation instrument calibration dates back to the 1980s
  • The instrument calibration service provides over 1400 calibrations per year to customers from the UK and internationally
  • We operate a management system accredited to "BS EN ISO 9001:2015"
  • All of our calibrations are traceable to national standards
  • Purpose-built laboratories with easy access from the Midlands motorway network
  • We have no formal links with any instrument manufacturer and provide unbiased expertise in all aspects of instrument calibration and repair
  • A 10-day turnaround is offered, although instruments can usually be calibrated quicker in urgent cases (please note, there may be an extra charge for this service)
  • We offer a basic electronics repair service (no repairs are carried out without your acceptance of our written cost estimate) 

Personal dosemeter irradiation

Our purpose built laboratories are available for bespoke calibration/type test work by prior arrangement.

A service is available for irradiation of personal dosemeters on either the ICRU body phantom, rod phantom or head phantom. A range of ISO narrow series X-ray beams from 15kVp – 300kVp (and at various angles) can be provided to assist you in meeting the performance requirements specified in BS 62387 “Radiation protection instrumentation – Passive integrating dosimetry systems for environmental & personal monitoring Part 1: General characteristics & performance requirements”.

Repair service

As part of our comprehensive calibration service we have a well-equipped workshop with experienced staff on site to offer a basic repair service.

All faulty equipment will be assessed and a repair cost estimate issued for the cost of the work required. No repairs are carried out without your acceptance of our written estimate.  

Please schedule a date with instrument calibration staff before dispatching any instruments.

The delivery address is:

Instrument Calibration Service
63 Melchett Road
Kings Norton Business Centre
B30 3HP

Diagnostic calibration service

Radiographic detectors/chambers

For calibrating diagnostic X-ray instruments, the Radiation Physics and Protection Service (RRPPS) produces the radiation qualities and irradiation conditions which are in accordance with the stated requirements of "CEI/IEC 61267: 2005, Medical Diagnostic X-ray Equipment - Radiation Conditions for Use in the Determination of Characteristics". X-ray spectra are available from 40 kV to 150 kV to measure the instruments performance over a broad range of energies.

IEC radiation qualities:

  • RQR2 - RQR10
  • RQC70
  • RQT8 - 10

The standard calibration also includes a linearity test, and all air kerma rates used are directly traceable national standards.

For kV meters, the kilovoltage is measured by determining the end-point of the x-ray spectrum by photon spectrometry using a hyper pure germanium detector.

Mammography detectors/chambers

Mammography chambers/detectors are calibrated to a range of kVs using a diagnostic mammography X-ray set with Mo anode, and 0.03 mm Mo filtration.

Mammography kVp Meters are calibrated against diagnostic mammography energies. The peak voltage is obtained from an invasive kV divider which has been cross referenced against the measured X-ray spectrum end point (peak photon energy) using a hyper pure germanium detector.

Radiation protection instruments

Maintenance and testing

IRR17 Reg. 20 specifies that radiation monitoring instruments are required to be properly maintained and tested at appropriate intervals by a qualified person. The Approved Code of Practice suggests a test, or calibration, at least annually.

Tests carried out by the Radiation Physics and Protection Service (RRPPS) are in accordance with the industry Good Practice Guide, GPG14, "The examination, testing & calibration of portable radiation protection instruments".

Any deviations from type test values (where available) and any significant change in instrument's response is reported clearly on the calibration report.

RRPPS takes part in national calibration inter-comparisons.

Protection doserate monitors

  • A single Cs-137 (662keV) source is used to provide a full range of traceable air kerma rates to confirm:
    • the instrument has a linear response over the full scale
    • the response of the monitor to high-energy radiations
  • An Am-241 source (60keV photon) is used to confirm that the energy response of the instrument does not vary significantly from the type test data
  • Instruments are tested up to the maximum doserate they are likely to encounter in practice
  • The instrument is tested to confirm that the display indicates off-scale for approximately 30 seconds during the high doserate test
  • Alarm levels (visual/audible) are checked
  • A directional dependence test is carried out on any new instrument, or an instrument that has had a significant repair since a previous calibration, to confirm the correct assembly of a detector. For example, energy compensation filters may be missing from a compensated Geiger-Muller detector
  • Electronic personal dosemeters are checked using a range of tests in accordance with Good Practice Guide 113 “The examination and testing of electronic personal dosemeters”. Alternatively, we offer a function test whereby the response of the instrument is checked against a restricted radiation / energy (Cs-137)

Contamination monitors

  • A range of large area reference sources are available. Each instrument is calibrated against those appropriate for each instruments’ type. The calibration sources are all constructed in accordance with ISO8769. They are constructed to provide a known surface emission rate for each radiation type (e.g. alpha, beta or photon) and energy. They are not designed in any way to replicate what the user might encounter in practice. Their purpose is to provide calibration services with a reliable, well-constructed, long lived source with accurately known surface emission rates so that comparisons with manufacturer's type test data may be made. The price of the calibration remains the same and is independent of how many sources are used to calibrate a monitor
  • Scintillation based detectors are exposed to a source of bright light to confirm they are light sealed and ambient light conditions have no effect on the instrument readings
  • Checks are carried out to confirm the instrument performs satisfactorily over its entire scale
  • For large area detectors, the uniformity of the detection area is confirmed with a small area source (usually 14C)
  • Geometry of calibration - the response is normally measured at a source - detector distance of 3mm. When assessing contamination in practice, this distance may not be achievable.  Corrections will need to be made to account for this and other factors that are explained in the National Physical Laboratory (NPL) Good Practice Guide GPG30, "Practical Radiation Monitoring"

My instrument is not functioning correctly. Can you repair it?

We offer a basic repair service. If an instrument needs a repair, we will give you a written cost estimate before commencing.

My instrument is brand new. Does it need a calibration?

Yes. If your instrument manufacturer has not done so already, your instrument requires a range of tests to be carried out to ensure it is functioning as the manufacturer intended, a pre-use test and routine calibration. There is no extra charge for a pre-use test.

I have a number of instruments but do not want them all calibrating at the same time. Can I schedule them in for calibration in smaller batches?

Yes. Simply contact the calibration service administrator to schedule the instruments at your convenience. We can schedule any remaining batches once you have received the first instruments back.

Do you provide a calibration for certain radionuclides, e.g. 99mTc?

No. Our sources provide us with a reproducible method to test your instrument to specific radiation types/energy. The qualified staff here at RRPPS can then decide if the instrument is functioning as it was intended. You can then be re-assured that the manufacturer's data in the manual or type test information can still be relied upon.

What range of doserates do you use?

Our 137Cs source has a traceable calibration from 1 µGy/h to a little over 1000 µGy/h. Higher doserates may be available using X-rays. 

Last reviewed: 05 March 2024