K-Type Thermocouple Surface Temperature Sensor - 6mm Washer Probe, 1M Metal Braid

Specifications

• Sensor Type: K-Type Thermocouple

• Probe Style: Washer / Ring Terminal

• Mounting Hole Diameter: 6.0mm (Ideal for M6 bolts)

• Temperature Range: 0°C to 400°C (Safe limit for fiberglass/braid insulation)

• Cable Length: 1 Meter (39.3 inches)

• Cable Shielding: Stainless Steel Metal Braid

• Internal Insulation: Fiberglass

• Terminal Type: 2x U-shaped Spade Terminals

• Strain Relief: 48mm Metal Spring

• Polarity Indicator: Red (Positive) / Blue (Negative)

Key Applications and Projects

• Engine Cylinder Head Monitoring: Bolting the sensor directly to the spark plug base or engine block of an RC car, go-kart, or motorcycle to monitor operating temperatures.

• Industrial Heater Blocks: Monitoring the surface temperature of massive aluminum heating plates on vacuum forming machines or injection molding extruders.

• Custom Coffee Roasters: Attaching the sensor to the metal roasting drum to feed highly accurate environmental temperatures back to a PID control loop.

Unlock New Capabilities (Project Evolution) The Automated Filament Dehydrator: 3D printing advanced materials like Nylon and Polycarbonate requires bone-dry filament. Instead of guessing the temperature inside a cheap food dehydrator, evolve your setup! Bolt this 6mm washer thermocouple directly to the metal heating element of your drying chamber. Connect it to an Arduino equipped with a MAX6675 module and a solid-state relay. You can now program a custom, hyper-accurate PID heating profile that keeps your filament perfectly at 85°C for 12 hours without ever risking a plastic meltdown!

Package Includes:

• 1 x 6mm Hole Washer K-Type Thermocouple Sensor (1 Meter Length)

FREQUENTLY ASKED QUESTIONS (FAQ)

1. What is a K-Type thermocouple? It is a temperature sensor made by joining two specific dissimilar metals (Chromel and Alumel). As the junction gets hotter, it generates a tiny, predictable voltage that controllers can read and translate into a temperature.

2. What does the 6mm washer hole do? It allows you to pass an M6 sized bolt or screw through the sensor, allowing you to clamp the sensor tightly and completely flat against a metal surface for superior heat transfer.

3. Can I use an M5 or M4 bolt to mount this? Yes. While the hole is 6mm, you can pass smaller bolts through it. However, you should use a metal washer over the smaller bolt head to ensure it clamps the ring terminal securely against your surface.

4. What is the maximum temperature this sensor can handle? The metal washer itself can withstand immense heat, but the fiberglass insulation and metal braided wire are generally rated for continuous use up to 400°C.

5. Why does it have a metal braided cable? The stainless steel braid provides intense mechanical protection against abrasion, cuts, and crushing. It also acts as an electromagnetic shield to prevent electrical noise from interfering with the tiny millivolt sensor signal.

6. Does the metal braid carry an electrical signal? No, the metal braid is just protective armor. The actual electrical signals travel through the two insulated wires hidden inside the braid.

7. What is the purpose of the 48mm metal spring near the washer? It is a mechanical strain relief. It prevents the wire from bending at a sharp 90-degree angle right where it connects to the washer, which would eventually snap the internal wires.

8. What are the red and blue spade connectors for? They are used to easily screw the thermocouple into the terminal blocks of a PID controller or amplifier board. Red usually denotes the Positive (+) lead, and Blue denotes the Negative (-) lead.

9. Does polarity matter when connecting a thermocouple? Yes, absolutely! If you wire it backward, the temperature reading will go down as the sensor gets hotter. If your controller reads negative temperatures when heated, simply swap the red and blue wires.

10. Can I connect this directly to an Arduino or ESP32? No. A thermocouple generates a micro-voltage signal that is far too small for a standard analog pin to read accurately. You must use a dedicated thermocouple amplifier IC.

11. What amplifier module do I need for my microcontroller? The MAX6675 (for 0°C to 1024°C reading) or the newer MAX31855 are the industry standards for interfacing K-type thermocouples with Arduino, ESP32, and Raspberry Pi via SPI communication.

12. Can I cut the wire to make it shorter? Yes, you can cut the wire and crimp on new spade terminals. Cutting it shorter will not affect the accuracy of the reading.

13. Can I splice regular copper wire to make it longer? No! You cannot use standard copper wire to extend a thermocouple. The splice joint will create a new "thermocouple" effect and completely ruin your temperature reading. You must use specific K-Type extension wire to lengthen it.

14. Can I immerse this washer probe in water or oil? It is not recommended. While the metal ring is fine, the crimped junction and the fiberglass insulation under the braid are not fully waterproof. It is designed for dry surface mounting.

15. How do I get the most accurate temperature reading from a surface? Ensure the surface is flat and clean. For extreme precision, apply a tiny dab of thermal paste (like computer CPU grease) between the metal washer and your surface before tightening the bolt.

16. Can I use this with a standard PID temperature controller? Yes, it is perfectly compatible with almost all industrial PID controllers (like the REX-C100 or Inkbird series) as long as you set the controller's input type to "K".

17. Is the metal washer electrically isolated from the thermocouple junction? In most of these grounded-junction designs, the thermocouple bead is welded directly to the metal washer for maximum thermal response. This means the washer is electrically connected to the sensor wires. Keep this in mind if you are bolting it to a surface carrying high live voltage.

18. What material is the washer made of? The washer is typically stamped from nickel-plated copper or standard stainless steel for a balance of durability and thermal conductivity.

19. Is this sensor flexible? Yes, the 1-meter metal braided cable is highly flexible and can easily be routed through drag chains or tight enclosures.

20. Can this be used to measure the temperature of an RC engine? Yes! Bolting this under a spark plug or onto an engine cooling fin is one of the most common applications for washer-style thermocouples, providing real-time telemetry for overheating prevention.