Ben Parker
Sales Manager
+44 (0)1372 378822
International Light Technologies Calibration Services ISO 17025 Accredited

International Light Technologies Calibration Services

ISO17025 Accredited calibrations

All instrumentation requires periodic re-calibration to ensure proper operation. In addition, extreme operating conditions (UV, heat, and dirt) can degrade optical performance potentially requiring an increase in re-calibration frequency. Annual re-calibration provides a relatively inexpensive guarantee of accuracy. Accurate readings translate into more efficient production processes, more reliable research and safer medical procedures.

International Light Technology's full service calibration lab offers ISO 17025 Accredited (UKAS recognised) calibrations and certifications that are also N.I.S.T. Traceable. 

Calibration and testing capabilities include Monochromators, Spectrometers, Spectroradiometers, Radiometers, Photometers, Lux meters, UV meters, UV, VIS and IR Light Sources, Photodetectors, LED’s, Lamps, Light booths, Filters, Cuvette transmission, Integrating spheres, reflectance standards and more. To verify that your system is supported, please visit the International Light website link here

If your specific system is not listed or if you have a question on our calibration services or capabilities, then please contact us directly.

Contact: Ben Parker
Sales Manager

+44 (0)1372 378822


Electrical Calibrations

Each Radiometer must be electrically calibrated in order to ensure accuracy and linearity to NIST standards. This is to ensure that the readings are an accurate representation of any signals received from a detector when light shines on it.

Most of ILT’s radiometers have storage space for several calibration factors. Slot one is traditionally occupied by the electrical calibration of the meter. Subsequent slots are usually for the detector calibration factors which can be made independent of the meter, however, we can also offer a meter-detector set to be calibrated together for even higher accuracy.

It is recommended that an electrical calibration is performed annually for accurate readings. For belt and other radiometers which have a build in detector, this calibration may be more often depending on the harshness of the environment the meter operates in.

Optical Calibrations

Each calibrated detector is comprised of the detector itself, any filters, the input optics, and the calibration. The input optic, for example a cosine diffuser, determines how incoming light will be spread on the detector. This will determine what units of measurement the detector is configured for as many optical units have a spatial dependence (for more information please see the input optics section of the light meters webpage). The filter determines how much for the incoming spectrum will be received by the detector. This, for example, may be something more functional, such as the F filter which creates a flat response for a silicon detector, which is more sensitive to longer wavelengths, or a photopic Y filter which mimics the response of the human eye and will result in a photopic detector response, and a different set of optical units. The detector senses the light after the input optic and filter and, in conjunction with the meter, governs the overall sensitivity and range of the measurement, as well as setting the maximum spectral range of the setup.

The calibration takes this combination and provides the user with an accurate reading on the meter for their units of choice and desired configuration. This calibration can be single point, either at the peak response of the detector or at a user defined wavelength, or scanned to give a large range of calibration factors of the wavelength range of the detector. This may be useful, for example, for measuring the power of several narrowband lasers using the same detector when the detector response is not flat across ass wavelengths. Spectroradiometer calibrations are created in a similar way.

Response Curve

A silicon detector where multiple calibrations may be required for different wavelengths due to the non-flat response.


An optical calibration should be made for every configuration that is used by a meter and will not be valid if the input optics change even for the same detector. We recommend that a detector is calibrated annually but this may be more frequent in more harsh environments. Filters and input optics should be well kept and undamaged for the duration of a calibration cycle.

Calibration units are measured in Amps per the unit you aim to measure. Typical calibrations are available for the following units: W/sr (Watts per steradian), W/cm2, microEinsteins/sec/cm2, W, W/sr/cm2, fl (footlambert), cd, lumens, and lux.

Supplier info:

For even more information, why not visit our suppliers website.