How temperature sensor calibration works: from order to accredited certificate

"Calibration" sounds like a stamp on paper. In reality it is a measurement: a specific sensor is compared against a reference standard and the laboratory records, in black and white, how far its reading deviates from the truth. Here is the whole process as it actually happens — and what an inspector sees at your site.

Who may calibrate at all

Slovak Act No. 157/2018 on metrology states in § 17 that calibration of an instrument subject to mandatory calibration is performed by the metrology institute or an accredited calibration laboratory. Nothing else counts — a supplier's in-house comparison is useful quality control, but it is not calibration in the legal sense. That is why every sensor we ship comes with a certificate from an accredited laboratory, with our own measurements serving only as an extra internal check.

The certificate belongs to the chip, not the paper

Every sensor carries a chip with an immutable 64-bit factory serial number — it cannot be rewritten or forged and can be read electronically at any time. The calibration certificate identifies the instrument by this number. Two practical consequences: the certificate remains valid wherever the sensor is deployed (it is tied to the instrument, not the site), and during an inspection the label on the sensor is matched to its certificate in seconds — our system stores the certificate right next to the sensor record.

What a calibration batch looks like

Sensors are calibrated in batches. Each unit gets a label with its code and serial number, and travels to the laboratory as a finished assembly including cable and connector — nothing is modified after calibration. The laboratory measures at points matching food-industry practice: typically −18 °C, 0 °C and +5 °C — freezer, critical limit and fridge. The output is a certificate stating the measured deviation and uncertainty for every point and every serial number.

How often to calibrate

The law does not fix an interval — the user sets it according to the purpose of measurement. Proven practice in food service: first check after one year (verifying the stability of new sensors), then a two-year cycle. With TempeStorm it is tied to regular sensor exchanges included in the price: we simply swap your sensors for freshly calibrated ones and the old units go back for recalibration. You handle nothing.

What your site gains at an inspection

Metrology inspectors want to see the instrument, an accredited calibration certificate and an instrument register. With TempeStorm you show all of it at once: the register is kept automatically, every sensor carries its certificate and validity, and temperature records write themselves. More legal background in Thermometer calibration for HACCP; accredited calibration is included in the sensor price — see the pricing.

Sources: Slovak Act No. 157/2018 Coll. on metrology (§ 17), Decree No. 533/2007 Coll.