There are 5 possibilities if the thermocouple doesn’t work stable: 1. Bad contact for terminal and thermal electrode: Solution: clean the terminal and thermal electrode retighten. 2. Insulation fails which may bring intermittent short circuit and ground connection. Solution: find the fault point, repair the insulation. 3. Intermittence of the thermode or measuring therminal. Solution: If the break point is on the measuring therminal, the break point should be welded ,or change the thermocouple. 4. insufficient installation or external vibration. Solution: Anti-detonation measures to install the thermocouple firmly. 5. External disturbance: Solution: Examine the interference source SICC group has become one of the leading professional manufacturers and exporters of bare thermocouple wires,mineral insulated cables,thermocouple and RTD probes our website:www.super-instrument.com.

The error in measuring temperature with thermocouples with any instruments is related several factors that combine together to affect the overall accuracy of the measurement: 1.Thermocople wire error:this is the error resulting from the fact that a given sample of bare thermocouple wire will not exactly meet the temperature versus millivolt relationship given the standard tables. The most accurate designation is for Type T thermocouple wire. The errors allowed for T type over the range -40 to 130℃ are 1.0 for standard wire and 0.5℃ for speical limits of error wire. 2.Reference junction error: this is the error in determing the temperature of the reference junction. Sometimes called “cold junction”. 3.Voltage measurement error: this is error in the measurement of the small voltage produced by the temperature difference between the measuing junction and the reference junction. 4.Linearization error: the temperature vs. millivolt relationship for thermocouples is inherently non-linerar. The accuracy of the conversion from voltage to temperature depends on the method that is used to make this conversation. Most commonly there is a fit to standard polynomials or interpolation within the table values. Both of these methods are subjection to some degree of error. SICC group has 20-year manufacturing experience in thermocouple wires, mineral insulated cable, thermocouple and RTD probes,get more details from us quickly.

The principle of thermocouple is base on the binding ability of metal atoms(ions) to free electrons in metals related to temperature, different kinds of metal atoms(ions) have different binding abilities to free electrons. The metal on both sides of the fusion interface after two kinds of metals are welded together has different binding ability to free electrons, the large one is positively charged and the other side is negatively charged. There is electromotive force (EMF) difference between the two sides of metals that be changed with the temperature, the value of EMF is small but can be accurately measured. 1.The practical use of thermocouple is not as simple as the above principle, sometimes the thermocouple need to be extended, the materials of thermocouple extension wire is not necessarily the same as the thermocouple metal material, as long as the temperature of the positive and negative joint is the same, it has no effect on temperature measurement. 2.Since the instrument measure the electromotive force, there is no current in the thermocouple wire in principle. 3.Since the EMF is very small, it is susceptible to various electromagnetic interferences in many cases, so be attention to this. 4.In some case, it is necessary to measure the temperature of the charged object, such as the temperature of wire joint, power terminal block, There are many instruments that can directly measure the temperature, but the thermocouple alloy wire has a high voltage that could be dangerous to the personnel, therefore the wires from the instrument to measured object need to be insulated from the personnel during the measurement, it must be powered off when adjust the contact points of the instrument and the measuring points. Get more information from www.super-instrument.com.