Description
The TEMA is a screw-in temperature sensor with a type K thermocouple and integrated measuring amplifier, manufacturer type Müller METS-TS.
It is screwed into pipelines and vessels and measures directly in the medium. The process connection ranges from 1/4" to 1" as well as from 1/4NPT to 1/2NPT; the protective tube made of 1.4571 stainless steel is Ø 6 × 0.5 mm with insertion lengths from 50 to 1000 mm; a 100 mm neck tube is available as an option. The system pressure is PN 25, protection at least IP 65 with encapsulated boards, any mounting position. The housing is made of PBT GF30, the display top of polycarbonate.
Sensor, measuring amplifier, display and two limit contacts sit in one housing: one device at the process connection, one signal to the control system, one value to read on site. A separate transmitter in the control cabinet is no longer needed. Setting is done with the keys at the display or over HART. The two limit contacts are PNP or NPN, 30 VDC / 200 mA, optionally 1000 mA.
The thermocouple is a type K (NiCr-Ni) with a tolerance of ±1.5 °C to DIN EN 60584-2 class 1; the measuring range runs from -50 … +200 °C with a minimum span of 50 °C. The amplifier works at 16 bit with an accuracy of 0.3 % of the range, 10 measurements per second, 20 ms response time and a filter from 0 to 99 s; the transfer characteristic is linear with temperature. The output is 4 … 20 mA with a superimposed HART signal in the 2-wire current loop, current range 3.8 … 20.5 mA with 3.6 mA on short circuit and 21 mA on break, supplied from the loop with 12 … 40 VDC and with reverse polarity protection.
Note before ordering: The ambient temperature is not the medium temperature – the medium may reach +200 °C, the electronics in the head only -20 … +80 °C; the manufacturer states explicitly for this series that temperatures above +85 °C can destroy the electronics. Which connector carries how many limit contacts is not a free choice: ten connections are available, but two contacts are only possible on M12 five- and eight-pin, on MIL and on the cable. Programming requires the DEV-KMA configurator with the TrComm software. No CE marking is documented in the manufacturer's data sheet, and no declaration of conformity is available. The Ex version of this design is the TEMD (METS-WTEx).
Benefits at a glance
- Type K thermocouple, ±1.5 °C to DIN EN 60584-2 class 1
- Medium -50 to +200 °C, minimum span 50 °C
- 4 … 20 mA with HART in the 2-wire loop, 0.3 % of the range
- Display and keys on the device, plus HART
- Two limit contacts, PNP or NPN
- Protective tube 1.4571, insertion lengths 50 to 1000 mm
- System pressure PN 25, protection at least IP 65