How does a thermocouple thermometer work Igcse?

How does a thermocouple thermometer work Igcse?

A thermocouple is used to measure very high temperatures or those that change quickly. Thermocouples contain two different metals. A voltage is produced where these metals meet inside the thermocouple. This voltage is directly related to temperature.

How do I make my thermometer more sensitive Igcse?

Some of the factors which increase sensitivity are:

1. Using a thermometer with a smaller glass bulb, as a smaller bulb contains less liquid and therefore, absorbs heat in a shorter time.
2. Using a narrow tube, as a small change in volume results in the liquid moving a larger distance along the tube.

Why is a thermocouple better than a thermometer?

The result is lower accuracy and faster wire degradation even under normal use. Thermocouples are sometimes avoided when total thermometer cost is very limited. The electronics required to read a thermocouple are more sophisticated and more costly than required for a thermistor.

What is the difference between thermometer and thermocouple?

A thermometer is a device that measures temperature or a temperature gradient (the degree of hotness or coldness of an object). A thermocouple produces a temperature-dependent voltage as a result of Seebeck effect, and this voltage can be interpreted to measure temperature.

What increases the sensitivity of a thermometer?

The sensitivity of a thermometer is defined as the increase in the length of the mercury column per unit increase in temperature.

Is thermocouple more accurate than thermometer?

Sensitivity: While both sensor types respond quickly to temperature changes, thermocouples are faster. A grounded thermocouple will respond nearly three times faster than a PT100 RTD. Accuracy: RTDs are generally more accurate than thermocouples. RTDs have typically an accuracy of 0.1°C, compared to 1°C for most.

What are the disadvantages of thermocouple?

➨(Disadvantages of thermocouple are): Non linearity, least stability, Low voltage, Reference is needed, least sensitivity etc. ➨(Disadvantages of RTD are ): Lower absolute resistance, expensive, current source needed, less rugged compare to thermocouples etc.