How Far Should the Brake Temperature Sensor Tip Be from the Brake Rotor or Drum?

The ideal distance depends on the type of sensor being used—specifically whether it is a contact thermocouple or a non-contact (infrared) sensor. Proper placement ensures accurate readings, avoids damage to the sensor, and improves repeatability during testing or race conditions.

Contact Sensors (e.g., RBTC Rubbing Brake Rotor Thermocouple)

For contact-based sensors like our RBTC Rubbing Brake Disc Thermocouple, the spring-loaded tip is designed to lightly touch the rotating brake rotor surface.

Tip Position: The sensor tip should just contact the rotor face—firm enough to stay in contact but not so tight that it causes excessive wear.
Distance: Effectively zero gap. The spring provides pressure, and the tip rides on the rotor.
Note: Since the tip is in physical contact, it will wear down over time. The RBTC is intended for short-term use in R&D and motorsports testing.

Maintenance Tip: Inspect tip wear regularly and replace when visibly worn. Avoid overtightening during installation to maximize tip life.

Non-Contact IR Sensors (Infrared Brake Temperature Sensors)

For infrared (IR) sensors, proper standoff distance is essential to ensure accurate thermal measurements without risk of heat damage or contamination.

Typical Distance: 1 to 3 inches (25–75 mm) from the rotor or drum surface.
Angle: Mount the sensor so it faces the rotor perpendicularly for optimal line-of-sight.
Avoid: Angled or obstructed views, which may cause inaccurate readings due to reflections or ambient heat interference.

Note: Always consult the manufacturer’s specifications for your IR sensor's ideal distance and field of view.

Drum Brake Systems

For drum brakes, temperature readings may target:

The drum exterior surface, if accessible
A backing plate or inside housing, near where heat builds up
Sensor Position: 1 to 2 inches away, depending on space constraints and sensor type

Reminder: Drum brake systems often retain more heat and have less airflow, so sensor placement should prioritize safety and airflow considerations.

Summary

Sensor Type	Recommended Tip Distance	Notes
RBTC Contact Thermocouple	Direct contact with rotor (spring-loaded tip)	Designed for short-term R&D use
Non-Contact IR Sensor	1–3 inches from rotor or drum	Maintain clear line-of-sight, avoid heat interference
Drum Brake Application	1–2 inches from housing or backing plate	Depends on component access

Still not sure how to mount your brake temperature sensor?
Contact our technical support team — we’ll help you choose the right sensor and placement for your application.