Digital Temperature Switches with Clamp-on Sensor

Aarhus/Staffanstorp/Swindon, May 5, 2008. With the digital temperature switches of the ETTN-YTTN range, Baumer’s product segment Process Instrumentation offers robust measuring instruments for temperature control for industrial process management. The devices are made completely of stainless steel and are particularly suitable for the use in severe industrial environments. A special design with a clamp-on sensor enables easy mounting at a pipe with two standard clips. It can measure the temperature of a process without direct contact to the medium.

Based on microprocessor technology, the temperature switches can be programmed completely on site by using code protected keys. They have two threshold outputs, PNP transistors or galvanic isolation. The output signal can be analogue (4 to 20 mA) or digital (RS485 Modbus). The devices can measure a scale from -200 up to +400°C with an accuracy of ± 0.5°C. Errors due to thermal resistance of the pipe or thermowell can be corrected by manually entering the process fluid temperature into the ETTN.

Depending on the version, the temperature measurement is conducted by a submerged probe or by surface contact over thermal conduction. This unique design is particularly appreciated because the temperature switch is mounted on the pipe with two standard clips, making any drilling unnecessary.

This mounting saves time and money for the end user and ensures a safe and reliable measurement: the sensing element is in contact with the pipe. There is a compensation for the ambient temperature. By entering the exact temperature of the fluid, an automatic correction can be made.

The devices are also suitable for hazardous areas (0, 1, and 2): The YTTN switches are offered as complete systems with ATEX intrinsic safety approved.