Ads
related to: are thermocouples interchangeable due to temperature
Search results
Results from the WOW.Com Content Network
A thermocouple produces a temperature-dependent voltage as a result of the Seebeck effect, and this voltage can be interpreted to measure temperature. Thermocouples are widely used as temperature sensors. [1] Commercial thermocouples are inexpensive, [2] interchangeable, are supplied with standard connectors, and can measure a wide range of ...
The two top thermocouple junctions are at temperature T 1 while the two bottom thermocouple junctions are at temperature T 2. The output voltage from the thermopile, ΔV , is directly proportional to the temperature differential, ΔT or T 1 - T 2 , across the thermal resistance layer and number of thermocouple junction pairs.
At the atomic scale, a temperature gradient causes charge carriers in the material to diffuse from the hot side to the cold side. This is due to charge carrier particles having higher mean velocities (and thus kinetic energy) at higher temperatures, leading them to migrate on average towards the colder side, in the process carrying heat across the material.
An alternative to the Pirani gauge is the thermocouple gauge, which works on the same principle of detecting thermal conductivity of the gas by a change in temperature. In the thermocouple gauge, the temperature is sensed by a thermocouple rather than by the change in resistance of the heated wire.
The Seebeck coefficient (also known as thermopower, [1] thermoelectric power, and thermoelectric sensitivity) of a material is a measure of the magnitude of an induced thermoelectric voltage in response to a temperature difference across that material, as induced by the Seebeck effect. [2]
Figure 2: [8] Working principle of a thermal laser sensor (Adapted from figure 3 with permission) As shown in Fig 2, a thermopile laser sensor consists of several thermocouples connected in series with one junction type (hot junction at temperature T 1) being exposed to an absorption area and the other junction type (cold junction at temperature T 2) being exposed to a heat sink.
One must be careful when measuring temperature to ensure that the measuring instrument (thermometer, thermocouple, etc.) is really the same temperature as the material that is being measured. Under some conditions heat from the measuring instrument can cause a temperature gradient, so the measured temperature is different from the actual ...
Example: I have a thermocouple with the hot junction at the temperature of 575 °C and cold junction at the temperature 550 °C. Let's say I measured the thermoelectric voltage U=0.1 mV. Now, I will take the same thermocouple with the hot junction on the temperature 50 °C and the cold junction on the temperature of 25 °C.
Ads
related to: are thermocouples interchangeable due to temperature