Thermocouple sensor placement and resistance - RDC Control - Canadian Thermocouple Manufacturer

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RDC Control- Canadian Thermocouple Manufacturer

10) Where should my sensor be placed?

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Thermocouple Introduction

Thermocouple Types

Thermocouples and Extension Wires


		Placement of the sensor in relationship to the work load and heat source can compensate for various types of energy demands from the work load. Sensor placement can limit the effects of thermal lags in the heat transfer process. The controller can only respond to the temperature changes it "sees" through feedback from the sensor location. Thus, sensor placement will influence the ability of the controller to regulate the temperature about a desired set point.Be aware sensor placement cannot compensate for inefficiencies in the system caused by long delays in thermal transfer. Realize also that inside most thermal systems, temperature will vary from point-to-point.

11) What should the thermocouple resistance measure?

		Although resistance cannot confirm the alloy has the correct thermoelectric specifications, it will check to see if other undesirable characteristics like opens, poor welds, or corrosion of the wires are present. Always measure the resistance of the thermocouple out of the application so the EMF output is not in conflict with the resistance meter. Ohms per Double Feet Long lead wire runs, or the use of analog based instrumentation, make conductor resistance an important consideration in selecting the wire gauge best suited for your application. The table below lists the nominal ohms per double feet for thermocouple and thermocouple extension wire. Ohms per double feet is the total resistance, in ohms, for both conductors, per foot. Click here to donwload the Nominal Resistance for Thermocouple Alloys table in PDF format. 1) What do thermocouple letter designations mean? 2) What are thermocouple color codes? 3) What letter of calibration should I use? 4) What is the initial accuracy of temperature sensors? 5) Is there a maximum length for thermocouples and thermocouple wiring? 6) What sheath material is the best for my application? 7) What are the maximum temperatures of thermocouples? 8) What type of junction should I use? 9) What is the response time of mineral insulated thermocouples? 10) Where should my sensor be placed? 11) What should the thermocouple resistance measure? 12) The sensor appears to be reading incorrectly. What might be wrong?