General purpose RTD with terminal head or
conductor extension lead wires for process and
laboratory applications
Application
The TH11 and TH12 temperature sensors are RTDs designed for use in the process
industry or factory automation type of environment. They consist of a measurement
probe with a RTD, insulation and sheath. Among other applications the sensors can
be used on:
- Heat exchangers, power & recovery area
- Carbon regeneration furnace or dryers
- Flue Gas, compressor stations
- Process reactors
Head transmitter
All Endress+Hauser transmitters are available with enhanced accuracy and reliability
compared to directly wired sensors. Easy customizing by choosing one of the
following outputs and communication protocols:
- Analog output 4 to 20 mA, with or without HART
- PROFIBUS ® PA
- FOUNDATION FieldbusTM
Field transmitter
Temperature field transmitters with HART® or FOUNDATION FieldbusTM protocol for
highest reliability in harsh industrial environments. Blue backlit display with large
measured value, bargraph and fault condition indication for ease of reading.
Your benefits
- High flexibility due to modular assembly with standard terminal heads and customized immersion length
- One source shopping for temperature measurement solutions. World class transmitter with integrated sensor offering for heavy process industry applications. Remove and install straight out of the box!
- Improved galvanic isolation on most devices (2 kV)
- Simplified model structure: Competitively priced, offers great value. Easy to order and reorder. A single model number includes sensor and transmitter assembly for a complete point solution
- All iTEMP transmitters provide long term stability ≤ 0.05 % per year
- Fast response time with reduced/tapered tip form
Measuring Principle
These resistance thermometers use a Pt100 temperature sensor according to IEC 60751. The
temperature sensor is a temperature-sensitive platinum resistor with a resistance of 100 Ω at
0 °C (32 °F) and a temperature coefficient α = 0.003851 °C -1 .
There are generally two different kinds of platinum resistance thermometers:
- Wire wound (WW): Here, a double coil of fine, high-purity platinum wire is located in a ceramic support. This is then sealed top and bottom with a ceramic protective layer. Such resistance thermometers not only facilitate very reproducible measurements but also offer good long-term stability of the resistance/temperature characteristic within temperature ranges up to 600 °C (1 112 °F). This type of sensor is relatively large in size and it is comparatively sensitive to vibrations.
- Thin film platinum resistance thermometers (TF): A very thin, ultrapure platinum layer, approx. 1 μm thick, is vaporized in a vacuum on a ceramic substrate and then structured photolithographically. The platinum conductor paths formed in this way create the measuring resistance. Additional covering and passivation layers are applied and reliably protect the thin platinum layer from contamination and oxidation, even at high temperatures.
The primary advantages of thin film temperature sensors over wire wound versions are their smaller
sizes and better vibration resistance. A relatively low principle-based deviation of the resistance/
temperature characteristic from the standard characteristic of IEC 60751 can frequently be observed
among TF sensors at high temperatures. As a result, the tight limit values of tolerance category A as
per IEC 60751 can only be observed with TF sensors at temperatures up to 200 °C (392 °F).