Response to study revealing inaccuracy in electricity meters
The ability of static electricity meters to measure correctly is currently a hot topic in Dutch, Norwegian and Dan-ish media. The question has arisen following a study carried out by a Dutch University (http://sciencebulletin.org/archives/10940.html), who has tested electricity meters from several manufacturers. We understand that media stories about electricity bills up to six times higher than the actual consumption are likely to worry consumers and spark further media interest in the question. Because of this, we have gathered some facts about Kamstrup electricity meters and their accurancy below.
Kamstrup meters have not been tested in the study carried out by a Dutch university.
The meters that display inaccuracies in the study all use either the Rogowski or the Hall measuring principle, whereas Kamstrup meters use the shunt measuring principle in all OMNIPOWER household meters and cur-rent transformers in OMNIPOWER industrial meters.
Every single Kamstrup meter is tested in accordance with current legislation before they leave our production facilities. All our meter types are approved according to the European Union's Measuring Instruments Di-rective (MID) and in that process they are also tested according to CLC/TR 50579, which refers to a test of immunity to conducted disturbances in the frequency range 2-150 kHz. This test is not a required part of the MID approval. Nevertheless, for the past five years we have tested all OMNIPOWER meters to this standard in order to be prepared for the above-mentioned issue.
Kamstrup Class B electricity meters comply with the ±1% accuracy limit stipulated in the MID. In fact, our own quality requirements are even stricter, as only meters with an accuracy within ±0.8% are released for distribution. Meters that do not meet the ±0.8% accuracy limit are analyzed and used for further quality im-provements.
The results of further tests carried out in March 2017 during which the meters were subjected to influence similar to the tests carried out by the Dutch University, show that even under these harsh conditions, Kam-strup meters maintain an accuracy within the above-mentioned limits.
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