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Knowledge from the field of electrical calibration

The electrical knowledge page answers your questions about electrical calibration. You will receive more detailed information on low frequency measurement technology, EMC tests and the calibration of oscilloscopes and resistance standards.

What does Testo Industrial Services mean by low frequency measurement technology?

Direct, but also indirect measurement methods, such as substitution, are used for this purpose. In addition, the calibration portfolio includes measurement modules, measurement cards and power meters from various manufacturers. Power meters are primarily concerned with the measurement of alternating quantities such as current and voltage, but also with their phase relationship to one another and the active and reactive power quantities derived from them.

How are oscilloscopes calibrated?

These are types of devices that allow the temporal representation of AC voltage up to a specific cut off frequency. For the calibration of these devices, on the one hand alternating variables are examined, but also, depending on the required cut off frequency, high-frequency typical procedures are applied. The determination of the cut off frequency or the specified wave impedance of the connection are two typical high-frequency measurement quantities in the field of oscilloscope calibration. We calibrate oscilloscopes with a bandwidth of up to 50 GHz fully automatically at a large number of measuring stations.

Electrical calibration

Why are EMC tests performed for immunity to interference?

To test the immunity to interference, normatively defined interference signals are generated with the aid of a pulse generator and applied to a device under test. To ensure that the normative requirements are met by the pulse generator, regular calibration is necessary.

How are resistance standards calibrated?

Reference standards are calibrated either by direct measurement or by the substitution method. In direct measurement, a known test current is applied to the standard and the voltage drop across it is measured. If a very high accuracy is required, the calibration is carried out in the substitution method via a so-called measuring bridge. This means that a known reference is set in comparison to the unknown standard to be calibrated. With the help of the measuring bridge we use, we achieve low measurement uncertainties and cover a wide measuring range.