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Testing intervals for medical devices: MTK and STK
Safety inspection every two years, down to the month; metrological inspection according to Annex 2, down to the year. Deadlines, responsibilities and a calculation example.
In short: The safety inspection (STK) is due at least every two years and runs down to the month; the metrological control (MTK) follows the deadlines of Annex 2 and runs accurate to the year. The operator of the device is obligated, not the dealer or the repair shop.
STK and MTK compared#
| Safety inspection | Metrological control | |
|---|---|---|
| short form | STK | MTK |
| Legal basis | § 12 MPBetreibV | § 15 MPBetreibV |
| Affected devices | Products according to Annex 1 | Products according to Annex 2 |
| deadline | at least every 2 years | 1 to 5 years, depending on the device |
| Start of the time period | upon expiry of the Month the commissioning or the last inspection | upon expiry of the year the commissioning or the last inspection |
| Responsible | the operator (clinic, practice, care facility) | |
| Proof | Record with date, result and measurements; retain until the next inspection. | |
Deadlines for metrological control (Annex 2)#
| Device | deadline | meant are |
|---|---|---|
| Non-invasive blood pressure monitors | 2 years | Upper arm and wrist devices, including long-term blood pressure monitors |
| Medical electrothermometers | 2 years | Contact thermometer with electrical measurement acquisition |
| Infrared radiation thermometer | 1 year | Ear and forehead thermometer without skin contact |
| Eye tonometer | 2 years | for measuring intraocular pressure |
| Diagnostic dosimeter | 5 years | Dosimetry in diagnostics |
Why the two deadlines are calculated differently#
This is the point at which appointments get delayed in practice. An example using the same device, last checked on March 14, 2024:
- STK: The deadline expires at the end of March 2024. Two years later it is on March 31, 2026 exhausted.
- MTK: The deadline expires at the end of 2024. Two years later it is on December 31, 2026 exhausted.
A nine-month difference despite the same inspection date. Therefore, anyone listing both dates in one document needs two separate calculation methods.
New for defibrillators from January 2027#
Automated external defibrillators for laypersons may be exempt from safety inspections if they are self-testing and undergo regular visual checks. For devices that from January 2027 Furthermore, before AEDs can be placed on the market, they must document their self-test results and transmit them to the operator via remote monitoring (§ 12 para. 2 MPBetreibV). Anyone procuring AEDs now should include this requirement in the tender specifications.
Frequently Asked Questions#
- How often should a blood pressure monitor be checked?
- Non-invasive blood pressure monitors are subject to metrological testing every two years. The period begins at the end of the year in which the device was put into operation or last tested (§ 15 MPBetreibV, Annex 2). A device tested in March 2024 is therefore compliant until December 31, 2026.
- What is the difference between STK and MTK?
- The safety inspection (STK) verifies electrical and functional safety and is due at least every two years, calculated at the end of the month (§ 12 MPBetreibV). The metrological inspection (MTK) verifies that the device measures correctly; its deadlines are specified in Annex 2 and expire at the end of the year (§ 15 MPBetreibV). STK is calculated on a monthly basis, MTK on an annual basis.
- Who is responsible for the examination?
- The obligation lies with the operator of the medical device, i.e., the clinic, practice, or care facility. A service provider can carry out the inspection, but the operator remains responsible for compliance with the deadline.
- How often should an ear thermometer be checked?
- Infrared radiation thermometers, which include ear and forehead thermometers, are subject to annual metrological testing. They therefore have the shortest testing interval in Annex 2 of the Medical Device Operator Ordinance (MPBetreibV).
- Is there an exception for defibrillators?
- Automated external defibrillators for laypersons may be exempt from safety inspections if they are self-testing and undergo regular visual inspections (§ 12 para. 2 MPBetreibV). Devices placed on the market from January 2027 onwards must additionally document their self-test results and transmit them to the operator via remote monitoring.
- What happens if a deadline is missed?
- The device must not be operated until the inspection has been carried out. Regulatory authorities review the records; missing documentation constitutes an administrative offense. The person conducting the inspection prepares a report including the date, result, and measurements, which the operator retains until the next inspection.
Inspection and maintenance by Nispel#
We conduct metrological and safety inspections of blood pressure monitors, long-term blood pressure recorders, thermometers, and other devices for a fixed price, including a report and inspection sticker. DHL handles the collection; you only need to pack the devices.
As of August 19, 2026. The legal basis is the Medical Devices Operator Ordinance as amended in 2025 (MPBetreibV at gesetze-im-internet.deThis overview does not replace legal advice; the authoritative text is the regulation in its currently valid version.