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1.4 ISO17025 certification with 3-point calibration data

All SHT33 can be uniquely identified by their serial number (read out command see paragraph

4.11). For each sensor an individual 3-point calibration is performed, accredited to ISO/IEC

17025:2017. The accreditation is performed and granted by the Swiss Accreditation Service (SAS),

a public institution of the Swiss Government. The accreditation is documented on the SAS website

under the name SCS 0158 can be downloaded from this link. The three calibration temperatures

are T =

−30 °C, T = 5 °C, and T = 70 °C. Measurement uncertainties and decision rules according

to the SAS are given in Table 3.

Metrological traceability of the calibration is in accordance to ch. 6.5 of ISO/IEC 17025:2017,

encompassing but not limited to NIST traceability or traceability to other national metrology

institutes, according to the CIPM Mutual Recognition Arrangement (CIPM MRA).

Reel-wise calibration certificates and data for each SHT33 can be downloaded through a web-

client and through an API from libellus.sensirion.com, which allows for efficient processing by

automated systems. For detailed documentation, kindly refer to the Libellus documentation.

Temperature

Expanded measurement uncertainty (k=2)*

Decision rule

−30 °C

0.40 °C

Shared risk (JCGM 106:2010, 8.2)

5 °C

0.20 °C

Shared risk (JCGM 106:2010, 8.2)

70 °C

0.20 °C

Shared risk (JCGM 106:2010, 8.2)

Table 3. Measurement uncertainty and decision rule for the accredited calibration according to Swiss

Accreditation Service (SAS). *Measurement uncertainties represent a confidence level of 95% using a

coverage factor of k = 2.