Very High Temperature (VHT) Sensor

Where continuously high temperatures in excess of 1250°C are expected the VHT series accommodates this application area.

At these high temperatures the choice of measuring element becomes restrictive and generally either a type 'R' (Pt-13%Rh/Pt) or a type 'S' (Pt-10%Rh/Pt) thermocouple would be selected. There are other types of thermocouple that operate in this very high temperature and above, but they are usually only used for other operational reasons.

Both the type 'R' and 'S' precious metal thermocouples provide only a very small signal output compared to the range of more common base metal thermocouples. At 100°C with a reference junction of 0°C most of the base metal thermocouples exhibit an output 10 times that of the type 'R' and 'S' thermocouples. It is generally advisable therefore when using type 'R' and type 'S', not to expect highly accurate measurements below around 800°C.