Calibration at temperature fixed points

Klasmeier’s calibration service calibrates standard thermometers (SPRT) by using ITS-90 temperature fixed points. Depending on the customer’s requirements, slim temperature fixed points with greater measurement uncertainties and primary “large” ITS-90 temperature fixed points in heat pipes or ISO towers with excellent measurement uncertainties can be used. The order of the fixed points at which calibration is performed results in falling temperatures for SPRT’s. To exclude thermometer drift, the water triple point is measured after each fixed point measurement and thus the drift of the temperature probe is controlled. In addition, each resistance thermometer is annealed at the highest operating temperature before calibration and the annealing drift is determined with the use of the water triple point. Self-heating errors and hydrostatic pressure effects are analysed and taken into account during calibration. The DAkkS calibration certificate is internationally accepted and can also be used abroad.