DigiDoc 5 - Accurate temps?

JoeKamel · 06-09-2004, 06:55 AM

Hey, just a question about the DigiDoc 5's. They seem to use the same type of thermistors as are on some boards (the type that just seem to stick up and touch the underside of the chips, and I've read in many posts on here that the thermistors on boards aren't accurate. So my question is how accurate are they exactly? Also, they ship with both the flat and bulb type thermistors and was wondering if either was more accurate than the other.

pHaestus · 06-09-2004, 10:10 AM

Guaranteed +/-3C I believe. Repeatability is of course better as long as you don't have to move the probe around every time to measure your temps.

Joe · 06-09-2004, 10:33 AM

theve shown some weirdness around strong emf's (electro magnetic fields) like those given off from the transformers for CCFL's and Neon's. Temps seem to wander at times around those.

pHaestus · 06-09-2004, 10:52 AM

The flat probes don't seem to be too robust either. I know I never felt very comfortable that the reading wasn't getting affected by the bending of the flat probes. You could see them drift away from the other flat probe used for air measurements over time if you put one on CPU and one near fan intake. What I mean is that you might find at day 1 that the two probes when taped together so they were in contact w/ one another would read say 0.2C apart. After a few weeks of using one of those probes on the side of a CPU for heatsink testing and moving it around, maybe they were 0.8C apart or maybe 0.2C apart still but in the opposite direction. Could just be native repeatability or could be affected by manipulating the wires I dunno.

superart · 06-09-2004, 10:54 AM

Quote:

Originally Posted by Joe

theve shown some weirdness around strong emf's (electro magnetic fields) like those given off from the transformers for CCFL's and Neon's. Temps seem to wander at times around those.

could this be because the EMF induces a a current, thus changing the voltage going through the wire, thus making the controler think that the resistance of the thermister is diferent than it actually is, thus reporting the temperature inacurately?

...thus showing that i like the word "thus" and that I often use runon sentences, thus demonstrating my lack of proficiency in the use of propper english

JoeKamel · 06-09-2004, 06:27 PM

Thanks for the info guys. I don't change my setups too often, I usually just buy a new one every three to four years so I'm not too worried then about fragility of the thermistors. Anyway, I just wanted to say thanks for the 411.

RoboTech · 06-09-2004, 08:44 PM

And they won't read below freezing...

Here are my test results when I reviewed the DD5+

DigiDoc 5+ Temp probe testing...

pHaestus · 06-09-2004, 11:43 PM

Does that hold for a wide temperature range though RoboTech? My guess would be no just from my playing with thermistors.

06-09-2004, 06:55 AM	#1
JoeKamel Cooling Neophyte Join Date: Feb 2004 Location: Da NBH Posts: 68	DigiDoc 5 - Accurate temps? Hey, just a question about the DigiDoc 5's. They seem to use the same type of thermistors as are on some boards (the type that just seem to stick up and touch the underside of the chips, and I've read in many posts on here that the thermistors on boards aren't accurate. So my question is how accurate are they exactly? Also, they ship with both the flat and bulb type thermistors and was wondering if either was more accurate than the other.

06-09-2004, 10:10 AM	#2
pHaestus Big Player Making Big Money Join Date: Aug 2001 Location: irc.lostgeek.com #procooling.com Posts: 4,782	Guaranteed +/-3C I believe. Repeatability is of course better as long as you don't have to move the probe around every time to measure your temps. __________________ Getting paid like a biker with the best crank... -MF DOOM

06-09-2004, 10:33 AM	#3
Joe The Pro/Life Support System Join Date: Dec 1999 Location: Denver, CO Posts: 4,041	theve shown some weirdness around strong emf's (electro magnetic fields) like those given off from the transformers for CCFL's and Neon's. Temps seem to wander at times around those. __________________ Joe - I only take this hat off for one thing... ProCooling archive curator and dusty skeleton.

06-09-2004, 10:52 AM	#4
pHaestus Big Player Making Big Money Join Date: Aug 2001 Location: irc.lostgeek.com #procooling.com Posts: 4,782	The flat probes don't seem to be too robust either. I know I never felt very comfortable that the reading wasn't getting affected by the bending of the flat probes. You could see them drift away from the other flat probe used for air measurements over time if you put one on CPU and one near fan intake. What I mean is that you might find at day 1 that the two probes when taped together so they were in contact w/ one another would read say 0.2C apart. After a few weeks of using one of those probes on the side of a CPU for heatsink testing and moving it around, maybe they were 0.8C apart or maybe 0.2C apart still but in the opposite direction. Could just be native repeatability or could be affected by manipulating the wires I dunno. __________________ Getting paid like a biker with the best crank... -MF DOOM

06-09-2004, 11:43 PM	#8
pHaestus Big Player Making Big Money Join Date: Aug 2001 Location: irc.lostgeek.com #procooling.com Posts: 4,782	Does that hold for a wide temperature range though RoboTech? My guess would be no just from my playing with thermistors. __________________ Getting paid like a biker with the best crank... -MF DOOM

06-09-2004, 06:27 PM	#6
JoeKamel Cooling Neophyte Join Date: Feb 2004 Location: Da NBH Posts: 68	Thanks for the info guys. I don't change my setups too often, I usually just buy a new one every three to four years so I'm not too worried then about fragility of the thermistors. Anyway, I just wanted to say thanks for the 411.

06-09-2004, 08:44 PM	#7
RoboTech Cooling Savant Join Date: Sep 2002 Location: Cincinnati, OH Posts: 229	And they won't read below freezing... Here are my test results when I reviewed the DD5+ DigiDoc 5+ Temp probe testing...

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