Structure
A typical threaded thermocouple consists of:
Thermocouple probe (sensor element): Made from thermocouple wire pairs such as K-type, J-type, T-type, or E-type.
Protective sheath: Usually stainless steel (SS304, SS316, Inconel 600, etc.), providing corrosion and heat resistance.
Threaded fitting: Standard sizes include M6, M8, M10, 1/4", 1/2", or 3/8" NPT/BSP, allowing direct installation into a threaded hole.
Connection head or lead wire exit: For electrical connection — can be a terminal head, mini plug, or cable lead.
️ Key Features
Easy installation — screw-in design ensures firm contact and good thermal conductivity.
Good sealing — thread and optional sealing gasket help prevent leakage in pressurized or liquid systems.
Replaceable and maintainable — simple removal for maintenance or calibration.
Versatile mounting — suitable for pipe walls, tanks, heat exchangers, or machinery.
⚙️ Common Applications
Industrial furnaces and ovens
HVAC and refrigeration systems
Chemical and petrochemical pipelines
Power plants and boilers
Food and pharmaceutical process control
Specifications
| Parameter | |
| Temperature Range | -200°C ~ +1200°C (depending on type and sheath) |
| Sheath Material | SS304 / SS316 / Inconel 600 |
| Thread Type | NPT, BSP, Metric (M8, M10, M12) |
| Thermocouple Type | K, J, T, E, N |
| Connection | Terminal head, plug, or cable lead |
Key Components (with diagram context)
Threaded fitting / mount — the part that screws into the process (pipe, tank, or fitting).
Sheath / protective tube — usually stainless-steel or other high-temp alloy; houses the internal thermocouple wires.
Measuring junction — the tip of the thermocouple where the two dissimilar metal wires join and sense the temperature.
Extension / lead wires — internal wires that carry the generated voltage to the connection head or terminal.
Connection head or terminations — where the external wiring is connected; often includes a protective head, conduit entry or cable exit.
Insertion length / probe length — the length the sensor extends into the medium or environment for measurement.
Sealing / gasket (optional) — ensures process medium (liquid/gas) does not leak past the threaded fitting.
Notes for Use / Specification
When specifying, you’ll often need to state thread size (for example: M10 × 1.5, ½″ NPT, etc).
Specify the insertion length (how far the probe goes into the medium) — this dictates response time and accuracy.
Choose the sheath material depending on medium (corrosive, high temp, gaseous vs liquid).
Choose the thermocouple type (K, J, T, etc) based on temperature range and environment.
Make sure to note whether the junction is grounded or ungrounded (affects response time and electrical noise immunity).
Ensure the connection head is compatible with your installation (explosion-proof, IP rating, etc) if applicable.
