We can offer calibrations for electric power quality parameters such as voltage, current and power for non-sinusoidal signals. Continuous calibration at RISE lays the foundation for quality-assured measurements.
The national laboratories are responsible for maintaining the national reference standards for each measurement quantity and spreading metrological competence and traceability to industry and society at large. The national reference standards are the highest level of traceability in Sweden.
A calibration performed at a National Laboratory fulfils all typical traceability and accreditation requirements that commonly exist in industry and society at large.
Various parameters determine the power quality
Electric power quality, or simply power quality, is a summary concept for assessing the quality of an electricity supply. There are a number of different parameters that determine the quality, such as voltage level, distortion, transients etc.
The instruments used to measure power quality are therefore multifunctional instruments. They are usually called power quality instruments. It is often the loads in the net that cause power quality deficiencies, but it can also be due to natural phenomena such as thunderstorms and incorrect connection measures b the grid owners. Both the proportion of "bad" loads and the proportion of "sensitive" loads have increased over the years, while the deregulation of the electricity market has led to more parties being involved in the supply of electricity in today's grids.
Harmonics affect the quality of electricity
Instruments for measuring voltage, current, power and energy are often used in far from ideal situations. Nevertheless, they are often calibrated only at ideal sinusoidal voltages and currents. This is partly due to tradition but also because it is much more difficult to measure in non-sinusoidal conditions.
RISE provides calibration of voltage, current and power for non-sinusoidal signals
Nowadays, you cannot to assume that all the voltages and currents of the electric grid are almost sinusoidal. An increasing proportion of motor loads are inverter controlled and the offices are filled with computers and other electronic equipment. Virtually all lighting in offices, business premises and industries consists of fluorescent lamps or LED lamps.
These loads do not draw sinusoidal current and they therefore produce large harmonic currents which in turn give rise to harmonic voltages.
The need for measuring instruments that measure correctly even under these conditions has increased sharply, both ordinary instruments and so-called power quality instruments. In many measurement contexts e.g. in connection with quality assurance, contracts or disputes, calibrated measuring instruments are necessary. A reference instrument is then needed, that should not only be able to verify instruments under ideal conditions but also when the waveform deviates from the sine form.
Proper function is required
A basic function of power quality instruments is to measure voltage, current and power and power factor, so these functions are calibrated in the same way as a regular watt meter.
An extension of the basic function is to measure and save temporary peaks and valleys of the voltage (dips, sags, swells). For proper function, reasonable settings are required for how often and for how long each measurement is made, but otherwise you rely on the instrument's normal voltage function and no extra calibration requirements need to be set.
The most common extra function is harmonic measurement, either to measure the content of individual harmonics or to measure the total distortion level. Now you can no longer rely on the instrument's usual voltage and current measurement, since harmonic measurements also place greater demands on frequency response and self-distortion.
Transients, flicker / flicker
Often the power quality instruments also have functions for transient measurement and flicker measurement.
With digital sampling technology as a basis, we have designed a reference instrument, a digital sampling wattmeter, which, in addition to calibration of the above-mentioned quantities, also can be used for calibration of reactive and apparent power, power factor and total harmonic distortion.
Our reference instrument has been found, partly through our own verifications and partly through international comparison measurements, to have a measurement uncertainty that is within ±150 ppm in most situations. Through extensive research and development work, we can now offer calibration of even the most accurate instruments on the market.
We issue calibration certificates in Swedish or English. You can retrieve your calibration certificate and more information regarding your measuring device, directly from our customer web site Calibration.
Order can be sent to firstname.lastname@example.org, or through the case management in our customer website Calibration.
Calibration of electric power quality instruments
Power meters, Electricity meters
Energy, Calibration, Generic metrology and measurement technology
National Measurement Centre
Price on tender
No preparation needed