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Australian Government: National Measurement InstituteAustralian Government: National Measurement Institute
National Measurement Institute

Time and Frequency Capabilities

NMI provides calibration services for time interval and frequency standards and instruments. Click here:

Before consigning an instrument for calibration always consult us to discuss your requirements. For further information contact

We also provide a time and frequency dissemination service. Click here for information on the operation of radio clocks in Australia


We calibrate atomic frequency standards, oscillators and other radiofrequency references. Measurements in certain microwave frequency ranges up to about 40 GHz are also available. The accuracy of frequency calibrations is generally limited by the noise characteristics and stability of the device being calibrated.

Frequency stability characterisation of frequency references through determination of the Allan variance, over averaging times longer than 10 s, may also be available at specified frequencies.

Instruments submitted for test should be fitted with coaxial or waveguide connectors and all output signals should be buffered to prevent loading errors. Setting of frequency references to a nominal value will only be carried out where the instrument has conveniently accessible adjustments. An owners manual should be supplied with the instrument but, if this is not available, information on power requirements and normal modes of use should be provided.    


We can calibrate a wide variety of time and frequency equipment including counters, synthesizers, phase meters, speed measuring instruments, tachometers, stroboscopes and stop watches.

Optical Frequencies

We are able to provide measurements of optical frequencies.