Thermocouple Thermometers

The thermocouple consists of the junction of two wires of different metals. At a given temperature, a potential difference results at the opposite extremes of the two wires (Seebeck effect), with the respective variations linearly related within small intervals. It is therefore possible to determine the temperature given the potential difference and characteristics of the two metals. The measurement end of the thermocouple probe is called the hot junction, while the connection of the thermocouple to the meter is the cold junction. An error is introduced as the cold junction is exposed to the ambient temperature. This error can be eliminated by physically putting the cold junction into an ice bath and forcing a reference temperature of 0oC, or by electronically compensating for the cold junction temperature effect. There are various types of thermocouples, identified by an ANSI code using a letter of the alphabet. The K type is the most commonly used thermocouple.

 

Thermocouple Thermometers

This category include K-Types, T-Types, and K, J, T-type thermocouple thermometers.
 

Thermocouple Thermometers with Calibration Feature

Although quite fast, thermocouple thermometers read with a response time much slower than other sensors and technologies. Unfortunately, the measurement of the thermocouple emf (electromotive force) loses accuracy because of the measuring system itself, based on the emf generated by the temperature difference between cold and hot junctions. The same emf may be generated under different conditions, for example:

Hot junction at 100oC; cold junction at 20oC; difference: 80oC or Hot junction at 90oC; cold junction at 10oC; difference: 80oC.

A temperature difference of 80oC is obtained with two different temperatures of the sample. It is, therefore, very important to determine the cold junction temperature very precisely. To solve the problem, Hanna offers thermocouple thermometers with a user calibration feature that allows the user to calibrate the measuring system in an ice bath at 0oC.

Thanks to this solution, it is now possible to use thermocouple thermometers for HACCP controls with an accuracy of ±0.3oC, which is the same performance of our Pt100 or NTC thermometers, but with a faster response time.

 

 

Thermocouple Thermometers The thermocouple consists of the junction of two wires of different metals. At a given temperature, a potential difference results at the opposite extremes of the... read more »
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Thermocouple Thermometers

The thermocouple consists of the junction of two wires of different metals. At a given temperature, a potential difference results at the opposite extremes of the two wires (Seebeck effect), with the respective variations linearly related within small intervals. It is therefore possible to determine the temperature given the potential difference and characteristics of the two metals. The measurement end of the thermocouple probe is called the hot junction, while the connection of the thermocouple to the meter is the cold junction. An error is introduced as the cold junction is exposed to the ambient temperature. This error can be eliminated by physically putting the cold junction into an ice bath and forcing a reference temperature of 0oC, or by electronically compensating for the cold junction temperature effect. There are various types of thermocouples, identified by an ANSI code using a letter of the alphabet. The K type is the most commonly used thermocouple.

 

Thermocouple Thermometers

This category include K-Types, T-Types, and K, J, T-type thermocouple thermometers.
 

Thermocouple Thermometers with Calibration Feature

Although quite fast, thermocouple thermometers read with a response time much slower than other sensors and technologies. Unfortunately, the measurement of the thermocouple emf (electromotive force) loses accuracy because of the measuring system itself, based on the emf generated by the temperature difference between cold and hot junctions. The same emf may be generated under different conditions, for example:

Hot junction at 100oC; cold junction at 20oC; difference: 80oC or Hot junction at 90oC; cold junction at 10oC; difference: 80oC.

A temperature difference of 80oC is obtained with two different temperatures of the sample. It is, therefore, very important to determine the cold junction temperature very precisely. To solve the problem, Hanna offers thermocouple thermometers with a user calibration feature that allows the user to calibrate the measuring system in an ice bath at 0oC.

Thanks to this solution, it is now possible to use thermocouple thermometers for HACCP controls with an accuracy of ±0.3oC, which is the same performance of our Pt100 or NTC thermometers, but with a faster response time.

 

 

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