For the Love of all things temperature

[MIRCS]

How on gods green earth do you convert resistance to degrees C and degrees C to mK and resistance to mK 

[scottbp]

Hoo boy, there's no straight answer here, that topic is so broad that there is an entire branch of zen masters at NIST devoted to finding answers to that very question.  It depends on what kind of PRT, RTD or thermistor you're using. For example, on the ITS-90 scale, a 100 ohm Pt385 platinum RTD is approximately 100.0 ohms at 0°C and 138.5 ohms at 100°C. And the relationship is not linear, it follows a curve. The values are different for each type of PRT, some are 25 ohms at 0°C and some thermistors are 1000 ohms at 0°C and the resistance goes down as the temperature goes up. Go do a search on ITS-90. For starters:

http://www.hartscientific.com/seminars/seminar-its90.htm

(No, I don't work for Hart Scientific.) Good luck on your path towards learning about temperature/ohm relationship...

[MIRCS]

Hoo boy, there's no straight answer here, that topic is so broad that there is an entire branch of zen masters at NIST devoted to finding answers to that very question.  It depends on what kind of PRT, RTD or thermistor you're using. For example, on the ITS-90 scale, a 100 ohm Pt385 platinum RTD is approximately 100.0 ohms at 0°C and 138.5 ohms at 100°C. And the relationship is not linear, it follows a curve. The values are different for each type of PRT, some are 25 ohms at 0°C and some thermistors are 1000 ohms at 0°C and the resistance goes down as the temperature goes up. Go do a search on ITS-90. For starters:

http://www.hartscientific.com/seminars/seminar-its90.htm

(No, I don't work for Hart Scientific.) Good luck on your path towards learning about temperature/ohm relationship...

Oh yeah............already been there and am still lost on it all. I'm just trying to get a budget done, were I have all the values the same as right now they are all different and it's driving me crazy.

[flew-da-coup]

How on gods green earth do you convert resistance to degrees C and degrees C to mK and resistance to mK 

Conversion Res to C depends on if it is an American Curve or Eurpean Curve for calculation. mK is 0.001 Deg C.

Mircs, I may be gogin crazy but I thought you knew more than me about temperature.

[MIRCS]

How on gods green earth do you convert resistance to degrees C and degrees C to mK and resistance to mK 

Conversion Res to C depends on if it is an American Curve or Eurpean Curve for calculation. mK is 0.001 Deg C.

Mircs, I may be gogin crazy but I thought you knew more than me about temperature.

You're not crazy..............I have all these values in different units and my freakin brain hurts from going over this over and over and over and over............plus I have a piece of crap 1127-2 that hates me, just got multiple network analyzers dropped off to be finished by 9/30, have 4 sets of gage blocks that need doing....................and I'm trying to write us an uncertainty budget for temperature............and then 5 torpedo TS became a priority for me a couple of hours ago.........as you can tell I'm frustrated

Yeah I had already used the conversion of being 0.001 Deg C, converting the mK to deg C. What really has me right now is converting the Resistance value of the high value and low value + their ranges which is in ppm to either mK or Deg C..........American curve 25.5 Ohm

That banging sound is my head you are hearing

[flew-da-coup]

How on gods green earth do you convert resistance to degrees C and degrees C to mK and resistance to mK 

Conversion Res to C depends on if it is an American Curve or Eurpean Curve for calculation. mK is 0.001 Deg C.

Mircs, I may be gogin crazy but I thought you knew more than me about temperature.

You're not crazy..............I have all these values in different units and my freakin brain hurts from going over this over and over and over and over............plus I have a piece of crap 1127-2 that hates me, just got multiple network analyzers dropped off to be finished by 9/30, have 4 sets of gage blocks that need doing....................and I'm trying to write us an uncertainty budget for temperature............and then 5 torpedo TS became a priority for me a couple of hours ago.........as you can tell I'm frustrated

Yeah I had already used the conversion of being 0.001 Deg C, converting the mK to deg C. What really has me right now is converting the Resistance value of the high value and low value + their ranges which is in ppm to either mK or Deg C..........American curve 25.5 Ohm

That banging sound is my head you are hearing

I hear you bro. I know how it is. My head is still spinning from this past week.

[hotncold]

This is my first reply to you guys.   I didn't see a response yet so here is some more info for you.   The change in resistance vs.  temperature for a 25. 5 ohm SPRT is approximately 0. 0001 ohm per 0. 001°C (1 mK).   This change is not completely linear across the scale.   More exact values are as follows:

Argon point (-189. 3442°C) is 0. 000111 ohms per mK.
Mercury point (-38. 8344°C) is 0. 000103 ohms per mK.
TPW (0. 0100°C) is 0. 000102 ohms per mK.
Tin point (231. 928°C) is 0. 000095 ohms per mK.
Zinc point (419. 527°C) is 0. 000089 ohms per mK.

I work in a big Pharma Metrology lab and I calibrate my own SPRT's using fixed points if that helps for my backround.   Let me know if you need more info.   I'll even tell you how much I make (seems to be a recurring theme on this website) if you ask real nice. . .