change kelvin to centigrade

[Paul Taylor]

Has any one built a circuit to change from kelvin to degrees centigrade? any help on this is much appreciated.

 

[legg]

On Wed, 27 Oct 2004 10:17:15 +0100, "Paul Taylor"
<paul.taylor@uea.ac.uk> wrote:

Has any one built a circuit to change from kelvin to degrees centigrade? any help on this is much appreciated.

What are you starting with, a signal level or data?

RL

 

[Paul Taylor]

Sorry, Yes I am starting with a signal level from a thermocouple chip.

-------------------------------------------------------
Paul Taylor BSC (Hons)
Electronics Technician
School of Environmental Science
University of East Anglia
Norwich
NR4 7TJ

Phone: +44 (0)1603 592502
Fax: +44 (0)1603 591327

Email: Paul.Taylor@uea.ac.uk
Web: http://www.uea.ac.uk/~e087

--------------------------------------------------------
"legg" <legg@nospam.magma.ca> wrote in message
news:ajrun0tskp826eubcrlirqul9gp4vr3qfm@4ax.com...

On Wed, 27 Oct 2004 10:17:15 +0100, "Paul Taylor"
paul.taylor@uea.ac.uk> wrote:

Has any one built a circuit to change from kelvin to degrees centigrade?
any help on this is much appreciated.


What are you starting with, a signal level or data?

RL

 

[Don Pearce]

On Wed, 27 Oct 2004 10:58:59 +0100, "Paul Taylor"
<paul.taylor@uea.ac.uk> wrote:

Sorry, Yes I am starting with a signal level from a thermocouple chip.

-------------------------------------------------------
If you really need to do this in the electronics, simply put a voltage

in series equivalent to the output at 0C, and of the opposite
polarity.

Far better though to get it into an ADC as quickly as possible, and do
it with Maths.

d
Pearce Consulting
http://www.pearce.uk.com

 

[Bob Stephens]

On Wed, 27 Oct 2004 10:06:00 GMT, Don Pearce wrote:

On Wed, 27 Oct 2004 10:58:59 +0100, "Paul Taylor"
paul.taylor@uea.ac.uk> wrote:

Sorry, Yes I am starting with a signal level from a thermocouple chip.

-------------------------------------------------------
If you really need to do this in the electronics, simply put a voltage
in series equivalent to the output at 0C, and of the opposite
polarity.

Far better though to get it into an ADC as quickly as possible, and do
it with Maths.

d
Pearce Consulting
http://www.pearce.uk.com

It's just a fixed offset of 273 degrees isn't it?

Bob

 

[Tim Wescott]

Paul Taylor wrote:

Sorry, Yes I am starting with a signal level from a thermocouple chip.

This should be a simple op-amp cookbook exercise to subtract an offset
and (possibly) multiply by a gain.

What are you using for a cold junction that you get an answer in Kelvin
instead of relative to room temperature?

--

Tim Wescott
Wescott Design Services
http://www.wescottdesign.com

 

[Rich Grise]

On Wed, 27 Oct 2004 10:17:15 +0100, Paul Taylor wrote:

Has any one built a circuit to change from kelvin to degrees centigrade? any help on this is much appreciated.

This is every circuit anybody's built, ever.

Degrees Kelvin Circuit o-----o Meter calibrated in Centigrade

Cheers!
Rich

 

[Rich Grise]

On Wed, 27 Oct 2004 11:47:59 -0400, Spehro Pefhany wrote:

On Wed, 27 Oct 2004 10:12:42 -0500, the renowned John Fields
On Wed, 27 Oct 2004 13:35:44 GMT, Bob Stephens
On Wed, 27 Oct 2004 10:06:00 GMT, Don Pearce wrote:
On Wed, 27 Oct 2004 10:58:59 +0100, "Paul Taylor"
Sorry, Yes I am starting with a signal level from a thermocouple chip.
It's just a fixed offset of 273 degrees isn't it?

~ 273.16°
'~' is right. ;-)
Maybe you're thinking of the triple-point (of water) = +0.01°C =
+273.16 K
0°C = -273.15 K

What would happen if anybody ever really achieved absolute zero?

Would the universe implode into the Final Black Hole?

Thanks,
Rich

 

[John Fields]

On Wed, 27 Oct 2004 11:47:59 -0400, Spehro Pefhany
<speffSNIP@interlogDOTyou.knowwhat> wrote:

0°C = -273.15 K

---
YOW!!!

That's REALLY cold!-)

--
John Fields

 

[Jonathan Kirwan]

On Wed, 27 Oct 2004 17:59:38 -0400, Spehro Pefhany
<speffSNIP@interlogDOTyou.knowwhat> wrote:

Almost unbelievably cold ;-) +, of course.

Temperature is better thought of in inverse-Kelvins. It does better at getting
the point across about absolute zero. T usually winds up in the denominator of
various expressions, anyway. Might as well elevate the idea to a multiplier,
where it belongs.

Jon

 

[Chaos Master]

Quoting Rich Grise [rich@example.net], that posted to sci.electronics.design on
Wed, 27 Oct 2004 20:52:00 GMT under article
<pan.2004.10.27.20.55.24.522213@example.net>:

'~' is right. ;-)
Maybe you're thinking of the triple-point (of water) = +0.01°C =
+273.16 K
0°C = -273.15 K

What would happen if anybody ever really achieved absolute zero?

Would be cool for some overclocking!
I can imagine a CPU cooled at this level.

[]s
--
Chaos MasterŽ, posting from Brazil.
"I know the difference between myself and my reflection. "
-- Evanescence, "Breathe No More"
http://marreka.no-ip.com | http://tinyurl.com/46vru | http://renan182.no-ip.org

 

[Pooh Bear]

Paul Taylor wrote:

Has any one built a circuit to change from kelvin to degrees
centigrade? any help on this is much appreciated.

You don't need a 'circuit' !

Degrees C = degrees K +273

How you choose to achieve the addition / subtraction ( either in
software or in harware ) and input and present the data is up to you.


Graham