RS PRO Type J Thermocouple 4mm Diameter → +350°C

Introducing the range of RS PRO Brake Pad Thermocouples, designed for low profile surface temperature measurement. They have been designed with a grounded sensing junction and a tin-plated copper washer for fast and accurate response and measurement, as well as include a 2 m fibreglass insulated, stainless steel overbraid cable that is attached to the stainless-steel thermocouple tip using a high temperature, ceramic-based sealant for optimum reliability.

Washer Thermocouple sensors are ideally suited for measuring surface temperatures, especially in applications where low-profile methods of temperature detection is required. They are most commonly used in:

• Research and development


• Motorsports testing


• Manufacturing, engineering and production environments

A thermocouple is a sensor used to measure temperature in a range of different processes and consists of two wire legs made from different metals joined together at their two ends to form two junctions. The hot junction, also known as the measuring junction, is connected to the body whose temperature is going to be measured, while the cold junction or reference junction is connected to a body of known temperature. When the measuring junction is placed on something hot a voltage or potential difference between this and the reference junction occurs. This voltage can then be converted into a temperature measurement using thermocouple reference tables. This process is also known as the Seebeck Effect.

This thermocouple is designed for measuring the temperature on a surface. Most thermocouples have a sensing tip where there ends of the thermocouple wires are encased in sheaths or protection tubes which do not allow for measuring the temperature of a surface area. In surface temperature sensing thermocouples, the exposed welded wire junction is housed in a magnet, adhesive patch, washer or bolt which provides a true surface contact. These thermocouple sensors are easy to install and use, the washer at the end of the sensor is simply positioned under a bolt or a rivet

RS PRO is our own brand range and brings you a wide range of high-quality, great value products offering you more choice. Trusted by engineers all over the world, every part of every RS PRO product has been rigorously tested against demanding industry standards