DAkkS (17025) calibration SPRT at temperature fixed points
(SPRT, Pt 25, Pt 2,5, Pt 0,25)

The DAkkS (17025) calibration of an ITS-90 standard thermometer is done at ITS-90 temperature fixed points.

SKU: 1403, 1412, 1428/1429, 1428, 1431, Category: Tags: , , , , ,


DAkkS (17025) calibration of a standard thermometer (WGa ≥ 1,11807 or WHg ≤ 0,844235) at the temperature fixed points (freezing points, melting points & triple points) of the ITS-90.

Achievable DAkkS (17025) measurement uncertainties including ITS-90 deviation function (k=2):

Temperature fixed points in °C Measurement uncertainties
Argon triple point -189,3442 °C 5 mK
Mercury triple point -38,8344 °C 3,5 mK
Water triple point 0,01 °C 2,5 mK
Gallium melting point 29,7646 °C 2,5 mK
Indium freezing point 156,5985 °C 5,5 mK
Tin freezing point 231,928 °C 3,0 mK
Zinc freezing point 419,527 °C 3,0 mK
Aluminium freezing point 660,323 °C 5,0 mK
Silver freezing point 961,78 °C 10 mK

The temperature fixed points are selected according to the temperature ranges of the ITS-90. You can see the temperature ranges of the ITS-90 here:

Before calibration, the standard thermometer is annealed. Hydrostatic pressure effects that occur in the temperature fixed point cells are corrected. The self-heating of the standard thermometer is investigated before the start of calibration and taken into account when calculating the calibration results. The resistance and W values of the standard thermometer are given as calibration results, and two characteristic curves (coefficients) are calculated according to the ITS-90 (with measuring current 0mA and 1mA, unless otherwise specified).

Calibration in the range argon (-189 °C) to the water triple point (0.01 °C) additionally includes the specification of a measurement uncertainty for extrapolation according to EURAMET TG 01:2017 (to the nitrogen boiling point ,~196 °C) with a measurement uncertainty of 7 mK (k=2).

The minimum immersion depth of the standard thermometer is at -189 °C: 400 mm, in the range -38 °C to 660 °C: 300 mm and at 962 °C: 450 mm. The maximum outer diameter is 8 mm.

Calibration time approx. 5-7 working days or by arrangement.


Including Klasmeier Cloud:
Our digital archive for your calibration documents


From now on you will find a QR code on all devices calibrated by Klasmeier,
with which you can quickly and easily access our digital archive in order to view your
calibration results.


Additional information

DAkkS Kalibrierung SPRT

DAkkS calibration extension Argon -189,3442°C, DAkkS calibration extension Indium 156,5985°C, DAkkS calibration from -189°C to 29°C, DAkkS calibration from 0°C to 660°C, DAkkS calibration from 0°C to 961°C