Thermocouples
Thermocouple wire, custom-length assemblies and accessories for temperature measurement, mapping and validation.
Withnell Sensors supplies premium Type T thermocouple wire, Autobond wire and Kapton-insulated thermocouples, alongside protective tip kits, feedthroughs and full-length wire spools.
Whether you need ready-made thermocouples or wire for in-house manufacture, our team can help you select an option suited to your application.
- Custom-length thermocouples manufactured in-house
- PTFE and Kapton insulation options
- Wire, tip kits and feedthroughs available
Custom Lengths
Thermocouples manufactured in-house to suit your installation and measurement requirements.
Choice of Construction
Select from Autobond wire, three- and seven-strand PTFE options, and Kapton insulation.
Application-Specific Options
Options for low-temperature measurement, steam applications and dry-heat processes.
Specialist Advice
Support with selecting suitable wire, insulation and accessories for your application.
Premium Grade Autobond Thermocouple Wire
Autobond thermocouple wire is designed to minimise water and steam migration along the wire. Its construction eliminates the outer clear PTFE jacket found on standard wire, addressing a common route for moisture ingress.
Available in two seven-strand wire sizes, Autobond combines the accuracy and uniformity specifications of standard Ultra-Premium wire with added protection against moisture migration.
- Available in 22 AWG and smaller 26 AWG wire
- Seven-strand construction
- Approximate temperature range: −200°C to +200°C
- Designed to minimise water and steam migration
PTFE 3 & 7 Strand Type T Thermocouples
Our premium Type T thermocouple wire is available in three- and seven-strand configurations, with individually insulated conductors and optional overall clear PTFE insulation.
The three-strand option is suited to installations where space is limited, such as narrow tubing or small filter housings. Seven-strand wire provides additional strength where more robust construction is required.
High-purity, uniform wire helps minimise measurement errors associated with material inconsistencies and mechanical stress.
- Three-strand wire: 1.88 mm major outside diameter
- Seven-strand wire: 3.05 mm outside diameter
- Three-strand option suitable for applications from −196°C to +200°C
- Optional overall clear PTFE insulation
Kapton Thermocouples
Seven-strand Kapton-insulated thermocouples are designed for dry-heat applications, including ovens and tunnels, at temperatures up to +350°C.
Kapton provides electrical insulation and mechanical performance at elevated temperatures. These thermocouples are manufactured in-house and can be supplied in custom lengths.
Kapton thermocouples must only be used in dry-heat applications, as moisture and oil can damage the insulation.
- Seven-strand, Kapton-insulated wire
- Temperature rating up to +350°C
- Suitable for dry-heat ovens and tunnels
- Manufactured to your required length
PTFE Tip Kits
PTFE tip kits use dual-shrink PTFE tubing to encapsulate the thermocouple tip, helping protect the measuring junction and extend sensor life.
A properly sealed tip helps reduce moisture tracking along the wire and oxidation of the thermocouple. It also helps prevent grounding-related measurement errors when the tip contacts a conductive surface.
- Helps minimise moisture tracking and oxidation
- Protects the thermocouple measuring junction
- Helps reduce grounding-related measurement errors
- Helps minimise air ingress around the junction during autoclave air-removal stages
Thermocouple Feedthroughs
Thermocouple feedthroughs provide a compact way to route multiple thermocouples into pressure or vacuum environments, including steam autoclaves and process pipework.
The assembly accommodates up to 18 individual thermocouples and uses a bayonet clasp, double silicone seal and pressure screw to secure the installation.
- Accommodates up to 18 thermocouples
- Maximum pressure: 5 bar
- Maximum temperature: +150°C
- Standard 1½-inch Tri-Clamp connection
Full-Length Thermocouple Wire Spools
For customers manufacturing their own thermocouples, Withnell Sensors supplies full-length wire spools alongside our ready-made, custom-length assemblies.
Choose from premium three- or seven-strand Type T thermocouple wire and Kapton thermocouple wire to suit your application and manufacturing requirements.
- Available in 1,000 ft and 2,000 ft spool lengths
- Premium Type T wire in three- and seven-strand options
- Kapton thermocouple wire available
- Suitable for in-house thermocouple manufacture
Talk to a technical specialist
We are always on hand to offer expert and impartial advice and technical support.
Our thermocouples and accessories support a range of temperature measurement and validation tasks. The appropriate wire, insulation and accessories depend on the temperature, environment and installation.
Pressure and vacuum processes: feedthroughs for routing thermocouples into vessels and process pipework within the assembly’s rated limits.
Autoclave validation: temperature measurement during steam processes using suitable thermocouples, tip protection and feedthroughs.
Temperature mapping: measurements at multiple locations within temperature-controlled equipment.
Pharmaceutical process monitoring: temperature measurement during manufacturing and validation activities.
Dry-heat ovens and tunnels: Kapton-insulated thermocouples for applications up to +350°C.
Low-temperature measurement: suitable Type T or Autobond configurations for low-temperature applications.
Selecting the right thermocouple means considering the complete assembly, not just the wire’s temperature rating.
Temperature and Environment
Tell us the minimum and maximum temperatures, together with any exposure to steam, moisture, oil, pressure or vacuum. Kapton insulation is intended for dry heat, while other constructions may be more appropriate for wet or steam applications.
Wire Size and Strength
Three-strand Type T wire is useful where space is limited. Seven-strand wire offers additional strength, while Autobond is available in 22 AWG and smaller 26 AWG options.
Length and Installation
Consider the distance between the measurement point and the recording equipment, any narrow access points, and whether a feedthrough or protective tip is required.
Recording Equipment
Let us know which data logger or validation system you use so we can discuss the required thermocouple type and connection.
Assembly Limits
The operating limits of the complete installation depend on the wire, insulation, tip protection and feedthrough. A wire’s temperature range should not be assumed to apply to every accessory used with it.
custom manufacture
Thermocouples made to your requirements
Tell us your application, wire type, required length and quantity. Our team will help you select a suitable configuration.
Hear From Our Customers
Our temperature mapping services support organisations across pharmaceutical, healthcare, food, manufacturing and laboratory environments where environmental control and compliance are essential.
