Metrological inspection (messtechnische Kontrolle) under the German Medical Devices Operator Ordinance. For devices with a measuring function, it checks whether the error limits are met.
The metrological inspection (messtechnische Kontrolle, MTK) is, under § 15 MPBetreibV, required for devices with a measuring function that are listed in Annex 2. These include audiometers, electronic and infrared thermometers, noninvasive blood pressure monitors, tonometers, therapy and diagnostic dosimeters and pedal ergometers. The MTK determines whether the device stays within the permissible maximum measurement deviations, the error limits. It is about measurement accuracy. The STK does include the measuring functions (§ 12(1)), but the MTK is still a separate duty with its own deadlines.
The intervals are set out in Annex 2 and range from one to six years depending on the device. They start at the end of the year in which the device was put into operation or last inspected (§ 15(5)). An MTK becomes due without delay when there are signs that the error limits are not being met, or when an intervention may have affected the device's measuring properties. Proper performance is presumed if the guideline of the Physikalisch-Technische Bundesanstalt, Germany's national metrology institute, is followed (paragraph 1). The operator may commission the authorities responsible for metrology, or persons and companies that meet the requirements of § 5 (paragraph 6).
For cost and scheduling, the difference from the STK matters: the interval is counted in years, not months. Annual planning follows from that, and similar devices can be bundled in the same year. After a repair or a drop, the MTK can become due immediately, even if the year is not over. Report and mark on the device are mandatory, as with the STK, and the report is kept until the next MTK (§ 15(7)). Ask for the MTK to be listed separately for each device on the invoice, so that you can tell which inspection was paid for.
What matters
- For each device, check whether it is listed in Annex 2 and record the deadline with the year.
- Have it confirmed that the performing body uses traceable standards and follows the PTB guideline.
- After repairs and interventions, clarify whether an MTK is due immediately.
- Keep the report until the next MTK and enter the result in the medical device log.
Suppose a medical practice has two noninvasive blood pressure monitors bought in different years. It tracks the MTK deadlines for each separately. After one of the devices has been dropped, it has the device checked metrologically right away, because its measuring properties may have been affected, instead of waiting for the regular date.
In the original wording
“The metrological inspections determine whether the device stays within the permissible maximum measurement deviations (error limits) stated in the guideline under paragraph 1, sentence 2.”
Unofficial translation
“Metrological inspections must be carried out without delay if […] there are signs that the device does not meet the error limits under paragraph 2 […]”
Unofficial translation