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c1a3m1
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Is it wrong to use a thermocouple to mesure the temperature of glass that will range from 20-300oC? as the range of the thermocouple is much higher, does this make it inaccurate?
on an exponential curve? surely you refer to the indication system (thermocouple and indicator), the pair may have linearity limits?Integral said:Sam,
...you use a thermocouple which has linear response in your region of interest.
Are we confusing accuracy with resolution?sam024 said:the greater the range of the measuring instrument, the less accuracy you will have.
Every instrument is inaccurate ? only the magnitude of the error varies.c1a3m1 said:...range from 20-300oC? as the range of the thermocouple is much higher, does this make it inaccurate?
The response charts I see for T/C is very nearly linear for large portions of the temperature range. None look exponential. Could you please provide a reference? (See my Omega link.) a T/C requires a very sensitive and stable voltage source for a reference (this can be used in place of a second junction and good millivolt meter for the measurement. In this respect they can be a bit hard for a home hobbyist to use. Though you can buy (for a price) temperature compensated temperature controllers which very easy to use.mechie said:on an exponential curve? surely you refer to the indication system (thermocouple and indicator), the pair may have linearity limits?
Are we confusing accuracy with resolution?
Every instrument is inaccurate ? only the magnitude of the error varies.
If you want the best accuracy then you could consider a resistance thermometer as these are generally considered to be better for this kind of temperature range.
Thermocouples are fine if you have a decent indicator - the question now becomes ... "what kind of accuracy do you want?"
A thermocouple works by measuring the voltage difference between two different metal wires that are connected at one end. When the wires are heated, they produce a voltage that is proportional to the temperature difference between the two ends. By calibrating the thermocouple with a known temperature, the voltage reading can be used to determine the temperature of the glass.
Type K thermocouples are commonly used for measuring the temperature of glass. This type of thermocouple is made of chromel and alumel wires, which can withstand high temperatures and have a wide temperature range. They are also relatively inexpensive and have good accuracy.
No, it is not possible to measure the temperature of glass with a contactless thermocouple. Since thermocouples work by measuring the voltage difference between two points, they require physical contact with the material being measured. Contactless temperature sensors, such as infrared thermometers, can be used to measure the temperature of glass from a distance.
Yes, a thermocouple can provide real-time temperature readings of glass. The response time of a thermocouple depends on the type and size of the thermocouple, but it can provide accurate readings within a few seconds. However, it is important to note that the temperature of glass can change rapidly, so continuous monitoring may be necessary for accurate measurements.
The accuracy of a thermocouple in measuring the temperature of glass depends on various factors, such as the type of thermocouple, the temperature range, and the calibration of the thermocouple. Generally, type K thermocouples have an accuracy of around ±2°C at temperatures ranging from 0 to 500°C. However, for more precise measurements, it is recommended to calibrate the thermocouple with a known temperature source.