What is a Resistance Temperature Detector?
Resistance Temperature Detectors (RTD), as the name implies, are sensors used to measure temperature by correlating the resistance of the RTD element with temperature. The element is usually quite fragile, so it is often placed inside a sheathed probe to protect it. The RTD element is made from a pure material whose resistance at various temperatures has been documented. The material has a predictable change in resistance as the temperature changes, and this function is called as temperature coefficient or Alpha value.
The temperature coefficient of pure platinum alloyed with other platinum group metals is set at 0.385 Ohm/K by the IEC 60751 publication. Other temperature coefficients may also be found in the United States and Japan where pure platinum is used, increasing the temperature coefficient up to 0.3916 Ohm/K or 0.3920 Ohm/K.Most PRTDs are constructed to have a nominal resistance of 100 Ohms at 0°C Pt100 but other types include Pt25,Pt50 etc .
EXOTHERM temperature detectors comply with the requirements of IEC 751 & DIN43760.Tolerances IEC 751 specifies
Class A and Class B, many customers specify tighter tolerances, typically specified as a fraction of the norm, for example 1/10th DIN. EXOTHERM always selects detectors at a tighter tolerance than that required by international standards.
Please refer to EXOTHERM tolerance chart for more data.
Ceramic wire wound RTD's allow the most accurate temperature measurement due to its construction. Platinum sensors with ceramic wire wound design have been the most reliable way to measure temperature in industrial applications.
All EXOTHERM detectors are wire wound platinum resistance types, ceramic housed. Known by a variety of names and terms
including temperature detectors, PRTD, (Platinum Resistance Temperature Detectors) or RTDS (Rresistance Temperature
These elements are constructed by starting with a helical coil of platinum sensing wire of known Alpha value. The coil is inserted into the internal bores of a high purity Alumina tube. Powder is then packed around the coil to prevent it from shorting and to provide vibration resistance during service. The manufacturing of this RTD's requires not only the highest quality raw materials but also strict process control at all stages of production.
Model No. Alpha Value Length Diamenter
ES-3028 3850 30 ± 0.50 2.8 ± 0.1
ES-2528 3850 25 ± 0.25 2.8 ± 0.1
ES-2028 3850 20 ± 0.25 2.8 ± 0.1
ES-3026 3850 30 ± 0.25 2.6 ± 0.1
ES-2026 3850 20 ± 0.25 2.6 ± 0.1
ES-2020 3850 20 ± 0.25 2.0 ± 0.1
ES-1520 3850 15 ± 0.25 2.0 ± 0.1
ES-1515 3850 15 ± 0.25 1.5 ± 0.1
ES-2515 3850 25 ± 0.50 1.5 ± 0.1
ES-3050 3850 30 ± 0.50 5.0 ± 0.1
Please note that all the above sizes are available in
Simplex (2 wire ) & Duplex (4 wire)
Customer specified sizes are available on request.
All the sensors are in accordance with IEC 751 (DIN 43760) standards