Where are electric resistance thermometers used?
Due to their accuracy and robustness, they are extensively used as in-line thermometers in the food industry. Within a wide range of temperatures the resistance of metals increases linearly with temperature. The measuring element is usually made of platinum.
What is a resistance thermometer used for?
Resistance thermometers are a type of sensor used to measure temperature. They are also known by a number of different names including Resistance temperature detectors (RTDs), Platinum resistance thermometers (PRTs) or Pt100 sensors.
What is electrical resistance thermometer?
Resistance thermometers, also called resistance temperature detectors (RTDs), are sensors used to measure temperature. Many RTD elements consist of a length of fine wire wrapped around a ceramic or glass core but other constructions are also used. The RTD wire is a pure material, typically platinum, nickel, or copper.
What are the disadvantages of resistance thermometer?
| THE RESISTANCE THERMOMETER (RTD) | |
|---|---|
| Advantage | Disadvantage |
| the platinum resistance detector is stable and resistant to corrosion and oxidation | RTDs do not allow point measurement of temperature because of the dimension of the sensing element |
What is the correct forehead temperature?
The difference between these two measured values, taking into account clinical equalisation calculations, gives the body temperature which is shown on the LCD display. The normal temperature range on the forehead is approximately between 35.4 °C and 37.4 °C.
Why platinum wire is used in resistance thermometer?
The most reproducible type of sensor is made from platinum because it is a stable unreactive metal which can be drawn down to fine wires but is not too soft. Using very pure wires, thermometers can be made with closely similar resistance characteristics and achieve good reproducibility in use.
Which is more accurate thermometer or thermocouple?
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 is the difference between thermocouple and thermometer?
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 are the advantages of a thermocouple thermometer?
Advantages:
- The thermocouple is less expensive than RTD.
- It has wide temperature ranges.
- It has good reproducibility.
- The temperature range is 270 to 2700 degree Celsius.
- It has rugged construction.
- It does not required bridge circuit.
- It has good accuracy.
- It has high speed of response.
How does a forehead thermometer work?
The forehead thermometers, like the electronic ear thermometers, use infrared technology to read heat. They use infrared sensors to measure the temperature of the superficial temporal artery, a sub-branch of the carotid artery.
What is a resistance thermometer?
Definition – The resistance thermometer or resistance temperature detector (RTD) uses the resistance of electrical conductor for measuring the temperature. The resistance of the conductor varies with the time. This property of the conductor is used for measuring the temperature.
What is an RTD thermometer used for?
Resistance thermometers ( Burns, 1999) or resistance temperature detectors (RTD) are based on the effect of temperature on the electric resistance of metals. Due to their accuracy and robustness, they are extensively used as in-line thermometers in the food industry.
Which thermometer is used to measure temperature?
Both electronic thermometers (rectal, oral, axillary sites) and infrared thermometers (forehead and tympanic membrane) accurately measure body temperature, although variability is greatest with the tympanic thermometer. A temperature reading of 37.8°C or more using any of these instruments is abnormal and indicates fever.