Description
The TSMA is a temperature sensor with a spring-loaded measuring tip, manufacturer type Müller MKTS-SP.
It is built for bearing and surface temperatures: the spring presses the tip against the measuring point with 14 mm of travel and keeps contact even when the component moves or expands with heat. That is exactly what it is for – a rigidly screwed-in sensor loses contact at such a point.
This sensor does not withstand process pressure. The manufacturer says so in as many words: the process connection has no sealing effect. It measures at the surface and in the bearing, not inside a closed medium; the pressure equipment directive is therefore not applicable.
The input takes one or two Pt100 or Pt1000 in 2-, 3- or 4-wire connection in classes A, B and AA, alternatively a type K thermocouple with a cross-band. The range runs from -50 … +150 °C at a smallest span of 50 K. As with the room sensor there are two versions: resistance directly on the connector, or 4 … 20 mA with HART in the 2-wire loop.
Total accuracy is 0.3 % of the range at 16 bit, the response time 20 ms, the measuring rate 10 measurements per second, the filter 0 … 99 s, the transfer characteristic linear with temperature. The current range is 3.8 … 20.5 mA with 3.6 mA on short circuit and 21 mA on break. Supply comes from the HART current loop with 12 … 40 VDC, load R = (UB − 12 V) / 21 mA, with reverse polarity protection. Setting is done in software over HART.
Mechanically: process connection 3/8", 1/2" or 3/4" without sealing effect, insertion length 45 or 65 mm as well as custom, sensor tube Ø 6 mm in stainless steel 1.4571, knurled screw 1.4541, compression spring in 1.4310 spring steel, PTFE insulating body, weight approx. 200 g. Protection is IP 65 at the electronics and IP 68 at the sensor, encapsulated inside. Without a transmitter the ambient may be -20 … +100 °C, with a transmitter only -20 … +80 °C.
Two notes: the ambient temperature is not the medium temperature – which neck length or insulation a hot medium calls for, the source does not say. And the MK product code is used three times by this manufacturer – MKTS, MKTS-GL and MKTS-SP, with a different meaning of the following digits in each case; when ordering, the type designation belongs in plain text, not just the code. Ten electrical connections are available; two sensors do not fit every connector.
Configuration uses the HART interface with USB and software, order number 01310-00220. No CE marking is documented in the manufacturer's data sheet and no declaration of conformity is available for this version. The version with IO-Link is the TSMB (MKTS-SPIO).
Advantages at a glance
- Spring-loaded measuring tip, 14 mm ±1 mm of travel
- Keeps contact on moving and expanding components
- Pt100, Pt1000 or type K thermocouple
- Range -50 to +150 °C, smallest span 50 K
- Resistance direct or 4 … 20 mA with HART
- Accuracy 0.3 % of the range, 16 bit
- Insertion length 45 or 65 mm, sensor tube 1.4571
- IP 65 at the electronics, IP 68 at the sensor
- Version with IO-Link available as TSMB