Temperature Measurement

Melt temperature sensors measure the temperature of the melt. There are various designs with more or less good results depending upon the configuration. Usually thermocouples are used for the measurement. Depending upon design however also RTD elements can be used. RTD elements have the advantage that they can be wired simply via copper cables. With thermocouples is to be taken care that the cables and connectors used must be of the same materials as the thermocouple itself. With thermocouple measurements one measures the temperature difference between measuring point (location of the sensor) and the evaluation location ( display or amplifier) this means that at the evaluation location a so-called cold joint compensation must be accomplished. The cold joint compensation is already integrated in ASENTEC temperature indicators.

Melt temperature sensors with measuring sword are ideal. These penetrate the melt with their measuring sword. Depending upon process a temperature distribution develops according to the depth of the measurement one point from this profile is measured over the cross section of the extrusion cylinder. One cannot use these melt temperature sensors however for every application.

The next best compromise is the use of melt temperature sensor with front-concise temperature measurement. This kind of melt temperature sensor does not penetrate the melt. Thus however only the temperature is measured close to the cylinder wall. Due to the construction additionally thermally influences from the cylinder heating can be seen.

For pure trend data combined pressure/temperature sensors can be used. The actual temperature measurement is done construction dependently behind the pressure diaphragm. Large influences by the cylinder heating are to be expected. Advantage of this solution is the use only one, possibly existing, melt pressure bore.

For special applications our engineers develop your specific solution sensor.. Our model TF x form i.e. a development for the analysis of the temperature distributions in a cylinder.