Fixed Point Calibration at The National Laboratory

Purpose

The national laboratories have are responsible for maintaining the national reference standards for each measurement quantity and spreading metrological competence and traceability to industry and society at large. The national reference standards are the highest level of traceability in Sweden.

A calibration performed at a national laboratory fullfils all typical traceability and accreditation requirements that commonly exist in industry and society at large.

Method

At present, RISE can realize the following eleven fixed points

• The triple points for water, argon and mercury
• The freezing points for indium, tin, zinc, aluminum, silver, gold and copper
• The melting point for gallium.

This means that RISE has the opportunity to directly reproduce the temperature scale according to ITS-90 in the entire range -189.3442 ° C to 2600 ° C.

Cell type fixing points

All fixing points are of cell type, ie a metal crucible, where the thermometer is inserted into a protective tube surrounded by the pure metal.

The thread method provides calibration up to 1600 ° C

We calibrate platinum-based thermocouples in both fixed-point cells and according to the so-called wire method. In the wire method, gold and palladium wires are melted in a tube furnace so that certain plateaus in the thermo-voltage curve are created, which allows calibration up to 1600 ° C.

We can offer complete fixed point calibrated platinum thermocouples with storage box and calibration table.

Deliveries

The calibration results are reported in a digital calibration certificate in Swedish or English which states that the calibration was performed at a national laboratory.