RTD Vs Thermocouple - Electronic Circuits Projects Diagrams Free

ohadne · 26th May 2009, 10:47 AM

Hi,
I wanted to know how does RTD (Resistance Temptature Detector) works? and how Thermocouple works?

and what is the difference between these two temp sensors?

Thanks,
Ohad.

Janis1279 · 26th May 2009, 12:02 PM

Please :
Thermocouple - Wikipedia, the free encyclopedia
Resistance thermometer - Wikipedia, the free encyclopedia

dknguyen · 27th May 2009, 01:21 AM

THermocouple- very high temperatures possible, relative temperature measurement only between two points, cheaper, more durable

RTD- more expensive, absolute temperature measurement, the most stable, the most accurate, linear (if you use the right material of course)

SPDCHK · 27th May 2009, 04:34 AM

Temperature Measurement with a Thermocouple or RTD

Leftyretro · 27th May 2009, 04:40 AM

Thermocouple utilizes Seebeck effect that says the dissimilar metals will product a small voltage proportional to temperature.

A RTD is a wound resistance wire (usually platinum) that changes resistance with temperature.

Lefty

ohadne · 27th May 2009, 09:31 AM

Hi Leftyretro,

yes i read about seeback effect, but i don't understand what happens to the metals when the temp is going up or down.
i mean to the current carriers (or electrical energy), are their number changed due to changes in temp?
and that is the reason for voltage that is created between the two junctions?

Thanks for your help.

ohadne · 27th May 2009, 09:32 AM

Quote:

Originally Posted by dknguyen

THermocouple- very high temperatures possible, relative temperature measurement only between two points, cheaper, more durable

RTD- more expensive, absolute temperature measurement, the most stable, the most accurate, linear (if you use the right material of course)

thanks for the info!

Leftyretro · 28th May 2009, 01:48 AM

Quote:

Originally Posted by ohadne

Hi Leftyretro,

yes i read about seeback effect, but i don't understand what happens to the metals when the temp is going up or down.
i mean to the current carriers (or electrical energy), are their number changed due to changes in temp?
and that is the reason for voltage that is created between the two junctions?

Thanks for your help.

You would have to research for the physics involved, much more in depth then can be put here. Lots on the Internet:

Thermoelectric effect - Wikipedia, the free encyclopedia

http://www.omega.com/temperature/Z/pdf/z021-032.pdf

ohadne · 31st May 2009, 08:29 AM

Hi All,

What does it mean when is written on electical device's specification the following:

Isolation Voltage: 3000V

Thanks.
Ohad.

ohadne · 31st May 2009, 08:30 AM

Thanks[

QUOTE=Leftyretro;745039]You would have to research for the physics involved, much more in depth then can be put here. Lots on the Internet:

Thermoelectric effect - Wikipedia, the free encyclopedia

http://www.omega.com/temperature/Z/pdf/z021-032.pdf[/QUOTE]

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26th May 2009, 10:47 AM	#1
ohadne	RTD Vs Thermocouple Hi, I wanted to know how does RTD (Resistance Temptature Detector) works? and how Thermocouple works? and what is the difference between these two temp sensors? Thanks, Ohad.

26th May 2009, 12:02 PM	#2
Janis1279	Please : Thermocouple - Wikipedia, the free encyclopedia Resistance thermometer - Wikipedia, the free encyclopedia

27th May 2009, 01:21 AM	#3
dknguyen	THermocouple- very high temperatures possible, relative temperature measurement only between two points, cheaper, more durable RTD- more expensive, absolute temperature measurement, the most stable, the most accurate, linear (if you use the right material of course) __________________ Tanaka Sensei (avatar) says: Please spell it "ridiculous" correctly! Not "rediculous". ^^ Last edited by dknguyen; 27th May 2009 at 01:21 AM.

27th May 2009, 04:34 AM	#4
SPDCHK	Temperature Measurement with a Thermocouple or RTD __________________ Don’t argue with idiots.......they will drag you down to their level and then beat you with experience!

27th May 2009, 04:40 AM	#5
Leftyretro	Thermocouple utilizes Seebeck effect that says the dissimilar metals will product a small voltage proportional to temperature. A RTD is a wound resistance wire (usually platinum) that changes resistance with temperature. Lefty __________________ Measurement changes behavior Last edited by Leftyretro; 27th May 2009 at 04:41 AM.

27th May 2009, 09:31 AM	#6
ohadne	Hi Leftyretro, yes i read about seeback effect, but i don't understand what happens to the metals when the temp is going up or down. i mean to the current carriers (or electrical energy), are their number changed due to changes in temp? and that is the reason for voltage that is created between the two junctions? Thanks for your help.

31st May 2009, 08:29 AM	#9
ohadne	Hi All, What does it mean when is written on electical device's specification the following: Isolation Voltage: 3000V Thanks. Ohad.

31st May 2009, 08:30 AM	#10
ohadne	Thanks[ QUOTE=Leftyretro;745039]You would have to research for the physics involved, much more in depth then can be put here. Lots on the Internet: Thermoelectric effect - Wikipedia, the free encyclopedia http://www.omega.com/temperature/Z/pdf/z021-032.pdf[/QUOTE]