Fischer Temprature Detector ThermocouplesBy ALVI
Application Thermocouples are suited for direct temperature measurement of gaseous and liquid media. The applications of the measuring inserts are not limited to the specified thermocouples. They are adapted to the given request with regard to temperature, length, bending property, vibration resistance and accuracy. In addition to our stanard models we provide a lot of special types for special applications. Important characteristics:
Thermocouples can be used in many fields of application thanks to the following characteristics:
• Cost-effective measuring principle
• Easy signal processing
• Possibility of use even at large distaces from the measuring point (w. transmitter)
• The thermocouples can be equipped with two measuring elements
• Easy exchange Construction and Operation
A thermocouple consists of two electric conductors that are made from different materials and are connected to each other at on end (measuring point). The thermoelectric potential developing at the reference junction depends on the materials of the thermo wires and the difference between the temperature at the measuring point and the reference junction. The temperature at the reference junction is to be kept at a constant level. If this is not possible the thermo wires can be extended by a compensating line. Compensating cables transfer the thermoelectric potential of the related thermocouples up to 200°C without any loss. The construction of the screw-in thermocouples described in this data sheet corresponds to the DIN 43770 and DIN 43771, some are further developments.
• Protective tube acc. to DIN 43772
• Connection head acc. to DIN 43729
• exchangeable measuring inset acc. to DIN 43735
The protective tube is designed as screw-in type for this type series. It protects the measuring insert and consequently the thermocouple against pressure, flow and possible damages. It remains installed and assures the continuation of process during an exchangement of the measuring insert. The construction of the protective tube depends on the pressure and temperature of the medium on site. See the load diagrams for the necessary specifications. The connection head in most cases consists of light metal, acc. to DIN EN 50446, type B. Other connection heads are offered at the end of this data sheet. The thermocouples are also available with an integrated 2- wire transmitter. See the data sheets TE41 for details! TT30..39 Screw-in Thermocoupls.