Flexible Mineral Insulated Thermocouple Cable (Type K) – Vibration Proof

For applications where space is limited or vibration is severe, the Hongtai Mineral Insulated Thermocouple Cable (also known as an MI Probe or Sheathed Thermocouple) is the ultimate solution. Unlike assembly-style sensors with hollow tubes, this probe consists of a metal sheath filled with highly compacted Magnesium Oxide (MgO) powder, which insulates the internal thermocouple wires.

This solid construction creates a Sheathed thermocouple probe that is incredibly durable, bendable, and responsive. It can withstand forces up to 50G, making it the standard for diesel engines, turbines, and complex machinery integration.

Key Technical Features & Benefits

• Unmatched Flexibility: The defining feature of a Flexible thermocouple is its ability to be bent into complex shapes. You can wrap it around pipes or route it through tortuous machine channels without damaging the sensor (Minimum bend radius is 2x the sheath diameter).

• Vibration Proof Durability: The compressed MgO thermocouple core locks the wires in place, preventing short circuits caused by mechanical shock. This is crucial for compressors, generators, and heavy motors.

• Super Fast Response: Because the Fast response thermocouple has a solid core and can be manufactured with small diameters (down to 0.5mm), it reacts to temperature changes in milliseconds—ideal for dynamic process control.

• Wide Temperature Range: Despite its flexibility, the Mineral insulated thermocouple cable can handle temperatures up to 1100°C (Type K with Inconel sheath).

• Long Lengths Available: We can manufacture continuous probes up to 100 meters long for deep well or large reactor mapping.

Technical Specifications (WRK Series)

Why Choose MI Cable Over Assembly?

1. Space Constraints: If your installation port is small or requires routing around corners, an Assembly thermocouple won’t fit. A Sheathed thermocouple probe can be snaked through the machine like a wire.

2. Pressure Rating: The solid internal structure allows MI probes to withstand much higher external pressures without crushing compared to hollow tubes.

3. Speed: For catching rapid temperature spikes (e.g., in exhaust manifolds), a thin diameter Fast response thermocouple is mandatory.

Application Scenarios

• Pipe Heat Tracing: The Flexible thermocouple can be strapped directly along the length of a pipeline to monitor skin temperature under insulation.

• Injection Molding: Inserting into small drilled holes in hot runner manifolds.

• Bearing Temperature: Monitoring motor and turbine bearings where vibration would destroy a standard sensor.

• Aerospace & Automotive: Exhaust gas temperature (EGT) sensors and brake testing.

FAQ

Q: How much can I bend it?

A: You can bend the Mineral insulated thermocouple cable to a radius of twice its diameter (e.g., a 3mm probe can be bent to a 6mm radius). Note: Do not bend repeatedly at the same point to avoid metal fatigue.

Q: What is the difference between Grounded and Ungrounded junctions?

A:   1. Grounded: The wires are welded to the tip of the sheath. This gives the fastest response time but can be susceptible to electrical noise (ground loops).

       2. Ungrounded: The wires are isolated from the sheath by MgO. Slower response, but immune to electrical interference. Recommended for VFD-controlled equipment.

Q: Can I cut the probe to length?

A: No. Unlike simple wire, an MI probe has a sealed tip containing the sensor junction. Cutting it destroys the sensor. Please order the exact immersion length required.

(Check our PID Controllers for precise control. External

Read about Mineral Insulated Cable Technology on ScienceDirect.)