Labfacility offer a wide range of thermocouple, PRT and extension cable / wire in stock for immediate despatch. Thermocouple cables are available in IEC or ANSI colour codes. Insulation types include PFA, PTFE, PVC & Fibreglass.

Which insulation Material?	Usable temperature range	Application Notes
PVC	-10°C to 105°C	Good general purpose insulation for 'light' environments.  Waterproof and very flexible.
PFA (extruded)	-75°C to 250°C	Resistant to oils, acids other adverse agents and fluids.  Good mechanical strength and flexibility.  PTFE better for steam/elevated pressure environments.
PTFE (taped & wrapped)	-75°C to 250/300°C	Resistant to oils, acids adverse agents and fluids.  Good mechanical strength and flexibility.
Glassfibre (varnished)	-60°C to 350/400°C	Good temperature range but will not prevent ingress of fluids.  Fairly flexible but does not provide good mechanical protection.
High temperature glassfibre	-60°C to 700°C	Will withstand temperature up to 700°C but will not prevent ingress of fluids.  Fairly flexible, not good protection against physical disturbance.
Ceramic Fibre	0°C to 1000°C	Will withstand high temperature, up to 1000°C.  Will not protect against fluids or physical disturbance.
Glassfibre (varnished) stainless steel overbraid	-60°C to 350/400°C	Good strength to physical disturbance and high temperature (up to 400°C).  Will not prevent ingress of fluids.

 

Wire and Cable Data
Thermocouple Wire
Twin, single conductor, having a temperature / e.m.f. relationship to the appropriate
standard over the complete temperature range.
Extension Cable
Twin, stranded conductors for connection between measuring thermocouple and
instrument ( or external reference junction) of the same materials as the
thermocouple and having the same e.m.f. / temperature characteristics over a
temperature range limited by the insulation material.
Compensating Wire or Cable
Twin, single or standard conductors for connection between measuring
thermocouple and instrument (or external reference junction) of different
composition from the thermocouple material, but having similar e.m.f / temperature
characteristics over a limited temperature range. Types U and Vx in Conductors
Table.
Connection of Themocouples to Measuring Instruments
Ordinary copper wires should never be used, as the error will be equal to the
diference in temperature between the connecting point of the thermocouple and
the instrument (or external reference junction).
Extension or compensating wire or cable must be employed, and it is essential that
the same polarity is maintained. If the polarity is reversed, the error is equal to twice
the temperature difference between the connecting point of the thermocouple and
the instrument (or external reference junction). For maximum accuracy extension
cables should be used, and the terminals and connectors should be of thermocouple
materials to maintain continuity.
Single / Multi-strand
The choice is mainly determined by the application (e.g. termination considerations
and internal diameter of associated sheath). Generally, single strand wires are used
for hot junctions, and multistrand for extensions of the thermocouple as being more
flexible. The greater the effective conductor diameter, the lower the value of
thermocouple loop resistance; an important consideration with long cable runs.