EN 13486 describes how to check that a temperature recorder or thermometer still measures within its class. It covers minus 80 to plus 85 °C and ties into the classes of EN 12830 and EN 13485. The 2023 edition replaced the 2001 edition.
Verification is required:
- For every new device.
- After any change in the measurement chain, a new probe for example.
- When a fault is indicated.
- After repairs.
Beyond that, the recorder owner and its client agree the interval, taking into account the manufacturer's requirements, mandatory regulations and the way the device is used (frequent temperature swings, vibration). Records built up over time count as evidence for adjusting it. The 2001 edition recommended a yearly check; the 2023 edition sets no fixed period.
The measurement is a direct comparison of the device with a working-standard thermometer, whose uncertainty may be at most 0.1 °C for class 0.2, 0.25 °C for class 0.5, 0.5 °C for class 1 and 1 °C for class 2. It is taken at the lowest and the highest point of the most frequently used range, with one more point in the middle when the range is wider than 10 K. For recorders the clock and the recording duration are tested as well. The result has to keep earlier measurements traceable and show that the device stays within its class until the next period.
