Temperature Sensor Accessories

The accessories required for a temperature sensor depend on how and where it is being installed. While many sensors can be fitted directly into the process, additional components can improve installation, protection, accuracy, and long-term reliability.

Common temperature sensor accessories include:

• Thermowells – Protect the sensor from pressure, corrosion, vibration, and flowing media while allowing it to be replaced without shutting down the process.
  
• Compression fittings – Enable adjustable insertion depth and provide a secure, leak-tight seal.
  
• Connection heads – House the sensor terminals or transmitters and protect electrical connections from moisture and dust.
  
• Temperature transmitters – Convert the sensor signal into a standard 4-20mA or digital output for PLCs, control systems, and remote monitoring.
  
• Extension and compensating cable – Used to extend thermocouple or RTD wiring while maintaining measurement accuracy.
  
• Mounting brackets and flanges – Secure sensors in ducts, tanks, vessels, or pipework.
  
• Terminal blocks and connectors – Provide quick and reliable electrical connections for maintenance or replacement.
  
• Protective glands and cable fittings – Help maintain the ingress protection (IP) rating and protect against moisture and contamination.
  

Choosing the correct accessories depends on the sensor type (RTD or thermocouple), process temperature, pressure, installation method, and environmental conditions. Using the right accessories not only simplifies installation but also extends sensor life, improves measurement accuracy, and reduces maintenance costs.

A thermowell is a protective sleeve that houses a temperature sensor, such as an RTD or thermocouple, shielding it from harsh process conditions while still allowing it to measure temperature accurately.

Thermowells are commonly used in pressurised systems, corrosive environments, high-flow applications, and processes where sensors may need to be removed for maintenance.

The main benefits of using a thermowell include:

• Protects the sensor from pressure, vibration, corrosion, abrasion, and aggressive chemicals.
  
• Allows sensor replacement without shutting down the process or draining the system.
  
• Extends sensor lifespan by reducing direct exposure to demanding operating conditions.
  
• Improves safety by maintaining the integrity of pressurised or hazardous systems during maintenance.
  
• Supports standardisation by allowing different RTDs or thermocouples to be used with the same thermowell.
  

Thermowells are manufactured in a range of materials, including stainless steel, brass, and specialist alloys, with threaded, flanged, or welded process connections to suit different applications. The correct thermowell should be selected based on the process temperature, pressure, flow rate, and compatibility with the process media.

Whether used in the food and beverage, pharmaceutical, chemical, oil and gas, or manufacturing industries, a correctly specified thermowell helps ensure reliable temperature measurement while reducing maintenance costs and downtime.

A compression fitting is a mechanical fitting used to securely mount a temperature sensor, such as an RTD or thermocouple, into a process while creating a reliable, leak-tight seal. It also allows the insertion depth of the sensor to be adjusted before being locked into position.

Compression fittings are commonly used in pipelines, tanks, vessels, ovens, and industrial machinery where the exact sensing position needs to be set during installation.

The main benefits of a compression fitting include:

• 
  Adjustable insertion depth to position the sensor exactly where temperature needs to be measured.
  
• Leak-tight sealing to help prevent the escape of liquids or gases.
  
• Secure mounting that keeps the sensor firmly in place, even in vibrating environments.
  
• Easy installation and removal without the need to weld or permanently fix the sensor.
  
• Suitable for a wide range of applications, from low-pressure systems to demanding industrial processes.
  

Compression fittings are available in a variety of materials, including stainless steel and brass, with common process threads such as 1/8", 1/4", 3/8", 1/2" BSPP, BSPT, and NPT. They are also supplied with different ferrule sizes to suit various probe diameters.

Selecting the correct compression fitting depends on the sensor diameter, process connection, operating pressure, temperature, and the compatibility of the fitting material with the process media. Using the right fitting helps ensure accurate temperature measurement, reliable sealing, and long service life.