Small Component, Big Impact
How temperature sensors with platinum measuring element PT100 better react to temperature fluctuations in hydraulic reservoirs and increase the energy efficiency of machines and systems
The temperature sensors made of stainless steel 1.4305 of type TS-SNA/SNK-PT100 from STAUFF are designed to determine and monitor the media temperature in hydraulic reservoirs. They cover a measuring range from -40 °C to +150 °C.
Thanks to the platinum measuring element PT100 used (in line with EN 60751, class A), the media temperature can be recorded significantly faster, more precisely and without the usual hysteresis of up to 35 °C compared to conventional bi-metal temperature switches.
Bi-metals form the basis of many conventional temperature switches. The temperature is detected by means of a bi-metal disc that switches abruptly when the switching point is reached. Normally closed and normally open contacts are available as switching functions. After cooling down to the reset point, the switch returns to its original state. The term hysteresis generally means the difference between the switching point and the reset point.
This allows immediate reaction to temperature fluctuations in the reservoir which can be communicated – e.g. to an external oil cooler – via the electrical connection of the sensor which is designed as a 4-pin round plug connector M12 with gold plated contacts (A-coded, in line with IEC 61076-2-101).
The amount of heat to be regulated in the tank is reduced and cooler performance and running time as well as the energy used are also clearly reduced. This results in less heat ageing of the hydraulic medium which may extend maintenance and replacement intervals under certain circumstances. It also has a positive effect on the durability of seals.
Typical areas of application include hydraulic applications which usually require the compensation of high temperature fluctuations to ensure proper operation of the systems and where there is a demand for optimising energy efficiency.
The simple installation process makes the TS-SNA/SNK-PT100 suitable for original equipment as well as for retrofitting during normal maintenance intervals or downtimes of your hydraulic systems.
- PT100 are so-called RTD sensors. The abbreviation RTD comes from “Resistance Temperature Detector.” So they are temperature sensors in which the resistance depends on temperature. When temperature changes, the sensor’s resistance changes also.
- PT100 are resistors with a nominal resistance of 100 Ω at a temperature of 0 °C as defined in IEC 751 and EN 6075 respectively.
- The letters PT refer to the material from which the resistor itself is made. In this case, PT is the chemical element symbol for platinum, as defined in the periodic table of the elements.
- PT100s are robust and largely insensitive to electrical interference, making them suitable for many applications, even in the vicinity of motors, generators and other devices that carry high voltages.
- In practice, mainly PT100 are used. However, the PT500 and PT1000 versions with higher nominal resistances of 100 Ω at a temperature of 0 °C are also common.
- PT100s are usually manufactured as thin-film or wire-wound resistors. Pure platinum is usually used for production as its resistance at various temperatures is known and documented. Any change in temperature results in a known, reproducible change in resistance, so that the temperature can be derived from the resistance.