FAQ

Very few calibration standards specify a calibration interval, so in most cases it is up to the user to define it.
However, there are recommendations – usually 12 months – and certain circumstances that make a calibration necessary, such as relocating the testing instruments or deviations. In any case, please note the following: If a deviation is found during a routine calibration, the time at which this deviation first occurred is unknown. Only the last calibration date confirms a fault-free condition. In other words: the shorter the calibration intervals, the shorter the period in which deviations may have occurred.

A statement of conformity is an assessment. To carry out an assessment, criteria must be defined (the conformity assessment criteria). This means that before the calibration, the customer and the calibration laboratory must agree on when an instrument is "OK" and when it is not. If the instrument then does not meet the requirements, the laboratory should respond and inform the customer immediately.

Yes. As we do not manufacture testing machines ourselves, we only calibrate testing instruments from other manufacturers – independently and for all makes.

In most cases, we calibrate directly at your premises. In special cases, instruments can also be sent to us. Please note: most instruments have to be recalibrated after being moved.

Depending on the type of machine, a calibration takes between two and four hours. Once all calibration work at your premises has been completed, you will receive your calibration certificate within 14 days.

The machine should be freely accessible, and an employee should know where the relevant accessories (e.g. other grips and fixtures) are kept. The ambient temperature should be kept as constant as possible, at least for the duration of the calibration.

With a factory calibration, the content of the calibration certificate depends solely on the issuer. The company carrying out the calibration decides on its scope and whether and how many results are stated. Furthermore, the method for determining the measurement uncertainty is not explicitly described. Traceability of the transfer standards used may be ensured, but is not monitored by any accreditation body.
With a calibration within a company's accredited scope (DAkkS calibration for short), the company carrying out the calibration must comply with the relevant calibration standard. If there is none, the laboratory must draw up its own procedure, which is then verified by the accreditation body. When calibrating in accordance with a standard, all results, including the stated measurement uncertainties, are comparable worldwide. In addition, the layout and design of the first page of a calibration certificate issued by an accredited calibration laboratory are prescribed throughout Germany.

After a testing instrument has been calibrated, you receive a calibration certificate, and a calibration label is attached to the instrument. Whether the instrument is suitable for your application, however, can only be seen from the calibration certificate. It usually states errors in % or classifications. Again, only the user can decide whether the stated error or class is sufficient for the intended use of the instrument. For example, if you test material with a tolerance of 10 %, you can also use an instrument with a stated error of 2 %. Either you correct the test result by the respective error, or you simply reduce the tolerance to, say, 8 %. Your customer usually requires a certain machine tolerance. For tensile, compression and flexural testing machines, class 1 is generally required. What exactly class 1 means is defined in the relevant standard – or simply ask your calibration service provider.
Before a calibration, for example, we ask you for the so-called conformity assessment criteria. This helps us to assess your instrument during the calibration and to give you an evaluation at the end.

This is the so-called overlapping measurement series. It occurs when the calibration laboratory uses a different measuring device during a measurement series. To ensure that both measuring devices are installed and used in approximately the same way, a measurement series is first calibrated with measuring device 1 and then the same measuring step with measuring device 2. The difference between the two measurements must not exceed the permissible deviation of the target class. The double measurement also confirms the accuracy of the measuring devices used by the calibration laboratory. As a rule, the deviations should not exceed 0.1 to 0.2 %.