Calibration

All instruments and systems from our product range are able to be calibrated traceable according to ISO9000 on request of the customer. You will definitely need calibration of measuring instruments used in your company for certification of your company according to ISO9001.

Quality benefits of measuring devices calibration performed by the manufacturer ZES ZIMMER:

  1. Our reference meters and standards are directly traceable according to ISO9000 to standards of the supreme national metrological institute, which is Physikalisch Technische Bundesanstalt (PTB) in Braunschweig.
  2. The accuracy of our standards is i.e. of: 33ppm of measuring value (m.v.) plus 66ppm of measuring range (m.r.) for current and voltage, and 50ppm of m.v. plus 33ppm of m.r. for active power.
  3. As manufacturer we can adjust the related product taking in consideration our comprehensive experiences of development and production. If applicable, product improvements of ongoing production can be adopted.
  4. General service, replacement of attrition parts and repair can be carried out the same time, when once having shipped your instrument to us.
  5. We are offering service and calibration contracts with term to be agreed between you and us, usually they are three year contracts.
  6. Process time for a calibration within our service center is only two days, in advance agreement of shipment date assumed. In case, you even can not bear this, maybe because of a 24/7 usage of the instrument at your production process, we can offer you for few cost only an at least equivalent equipped instrument.
  7. Our calibration protocols are of premium quality and will satisfy even supreme requirements:
     Used standards are identified by serial number and their accuracy, detailed description of the applicable calibration process, deviation of each measuring point and difference to acceptable inaccuracy, in other words not only a bad or good statement.
     Not only current and voltage, but also active power and energy are listed in our standard protocols (see demo calibration certificate). This differs from some third party calibration labs.
  8. Simple procedure: Just use linked form for requesting a quotation. Please fill in type of instrument, serial number and requested calibration services. We will send back that form with current price as a valid quotation. You can easily send that quotation then with your company seal and sign as your order.
  9. Calibration of special points: For calibration points, which are not part of an usual calibration certificate, there is on request and confirmation a special traceable calibration possible. I.e. in case of a very small power factor of 0.001.

Calibration of third party labs

Of course, there is calibration also possible performed by third party labs. Due to our experiences with third party labs, we recommend to check following points before placing an order there:

  1. Are used standards at least three times better in accuracy then the EUT, in terms of the calibration point (amplitude, frequency, phase error)?
  2. Are used standards traceable calibrated, also regarding active power? Are those certificates available to verify?
  3. Is there a detailed and applicable description of the calibration procedure? Which measuring instruments are applied with which signals in which ranges?
  4. Are there complete data on the measuring protocol, for you to follow up the calibration procedure?

+++ Traceable Calibration of Harmonics +++

Also measuring instruments designed according to IEC61000-4-7 to measure harmonics according to IEC61000-3-2/-12, IEC61000-3-12 and IEC61000-4-30 have to be calibrated regularly.
 
Quite recently it was not possible to calibrate harmonics as such traceable to any national or international standard. The reason was simple: Such a standard didn't exist. Instead single frequency currents were applied to assess the correct behavior of an instrument. This method had several disadvantages: It showed only the response to an individual frequency and not the response to a mix of many harmonics like in real world. Secondly the rise time (di/dt) of a single harmonic is much smaller than the rise time of a complex signal like the current drawn by a rectifier with capacitive load. To call this method traceable for harmonics seems not to be justified, it was only traceable for single frequencies.
 
Everybody who used harmonic analyzers and was certified according to ISO9000 or by test laboratories like VDE had to use this old, unsure method as there was no better one.Now for a short time PTB (Germany's authority for calibration) offers a method to apply many current harmonics at the same time with a well known accuracy. By this it is possible to generate real world signals with real world rise times to the equipment under test. ZES ZIMMER is one of the first companies achieving calibration certificate for their reference instruments for harmonics from PTB. So we are now able, to offer our customers also a real traceable calibration service for this special application.
 
Our reference instruments are calibrated at the classes A and B as well as typical classes C and D limits, which are the points of major interest.
 
Every serious test lab should use a serious calibration method for their analyzers, at least if they want to work according to ISO9000, which requires a traceable calibration.
 
Beside to development and manufacturing of necessary measuring instruments ZES ZIMMER offers the traceable calibration of harmonics as a service.