Maximize Temperature Accuracy by Extending Thermocouple Wires

Length does not affect accuracy; however, equipment that produces electrical noise that superimposes onto sensor signals and creates inaccurate measurements should be avoided.

Use extension wire with the same alloy composition as your thermocouple to ensure accurate measurements and avoid ground loops.

Thermocouple Extension Wires

Thermocouples play an integral part in many applications ranging from industrial manufacturing and gourmet cooking, to space exploration. Acting as temperature measurement sentinels, thermocouples provide crucial data that help control systems deliver excellence across diverse operations.

But thermocouple systems can be negatively affected by factors like wire length and use, ground loops and incorrect installation. Utilizing extension wires that match the type of thermocouple can help mitigate such errors.

At thermocouple extension cables are comprised of alloys tailored specifically for thermocouples. This prevents dissimilar metals from interfering with voltage generated at the cold junction and leading to inaccurate temperature readings, and they’re color coded to correspond with sensor calibration. They’re also insulated and jacketed in materials resistant to extreme temperatures, chemicals, abrasion, oil and solvents to prolong performance and reliability while available in various lengths.

Thermocouple Extension Cables

Kamet offers an extensive range of thermocouple extension wires to connect thermocouples in process pipelines with instruments at control centers. Their cables come equipped with thermocouples, extension, compensating cables and even compensating cables to meet every application need.

Extension cables used with thermocouples must match the base metal of their sensor (J, K or T); dissimilar metals could disrupt voltage generation at the sensor and give inaccurate temperature readings. To reduce noise pickup from electromagnetic fields near power lines and motors, they should also be shielded.

Extensions designed for high accuracy use a combination of standard and special limits of error wire, increasing thermocouple accuracy by using higher purity alloys and minimizing errors due to thermal cycling. Twisted and shielded cables help minimize electrical noise pickup; their insulation usually stands up to temperatures up to 650degC and their part numbers typically start with “EX.” Expendable thermocouples used in uniformity surveys or system accuracy testing must be built specifically to handle such temperatures; their insulation materials cannot be made available as common extension grades.

Thermocouple Extension Blocks

Thermocouple sensors are an integral component of many temperature measurement applications. Appropriate selection and installation will help achieve accurate temperatures that improve product quality as well as production efficiency.

Un often-made mistake by users is using standard copper wire instead of thermocouple extension wire, leading to incorrect temperature readings due to the various metals present.

An extension grade wire will help avoid these errors by maintaining total loop resistance at 100 ohms or below, preventing electrical noise from disrupting signals and meeting Special Limits of Error for each thermocouple type.

Another key consideration when running thermocouple extension wire is keeping it away from power lines as much as possible, since low voltage thermocouple signals generated by dissimilar wires are extremely susceptible to interference from nearby powerlines. To mitigate interference issues, Thermocouple Extension Blocks have protective heads and screw terminal connections designed specifically to match specific TC types, providing reliable temperature readings over extended time periods. These blocks also feature special isothermal junctions to maintain stable measurements over extended timeframes.

Thermocouple Extension Kits

Thermocouples have long been recognized as an affordable means of measuring temperature across a range of applications – from cryogenics to jet engine exhaust. Composed of two metal wires connected by soldered joints, thermocouples provide a voltage output proportional to any difference in temperature at their junction.

Data acquisition hardware that supports thermocouple type input allows voltage signals to be converted into accurate temperatures using a lookup table, but there may be limitations with this approach; specifically the voltage signal may be small and nonlinear relationship between temperature-voltage must calibrated with reference junction.

A thermocouple’s maximum usable length depends on both total loop resistance and electromagnetic noise affecting its signal, such as through shielded wire or metal conduit with guards to help minimize electric field pickup and potential interference from power lines that might obstruct its path. For optimal use, keeping these wires away from power wires could eliminate such interference that might obstruct thermocouple signal transmission.