Temp Probes- Question re operation of - diyAudio
Go Back   Home > Forums > Design & Build > Parts
Home Forums Rules Articles diyAudio Store Gallery Wiki Blogs Register Donations FAQ Calendar Search Today's Posts Mark Forums Read

Parts Where to get, and how to make the best bits. PCB's, caps, transformers, etc.

Please consider donating to help us continue to serve you.

Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving
Thread Tools Search this Thread
Old 27th September 2005, 06:39 AM   #1
lgreen is offline lgreen  United States
diyAudio Member
lgreen's Avatar
Join Date: May 2003
Location: San Diego, USA
Default Temp Probes- Question re operation of

I've got an Aerogate 3 fan controller running the fans in my amp and monitoring all heatsinks in the amp via 4 wired temp sensors which are black dual wires which meet at a sensor tip covered in kevlar or some similar tape. I've also got a DMM with a temperature probe-- a single metal tip that splits into to leads down the wire somewhere and plugs into a portable DMM in the normal + and - inputs to work only when temp is selected.

My question is how do these dealies work to sense temperature. I'm asking for 2 reasons-

1. I'd like to sense the temp of live heatsinks and both products say to probe isolated heat only. I can use insulators and thermal compound, but i'm already doing that and want a direct measurement.

2. I've fastened some of the Aerogate sensors underneath some plastic blocks (with thermal compound) but the mounting is pushing the sensors down to the heatsink with massive force. If the sensor requires a physical deflection due to heat I'm thinking my method of mounting might tend to give me lower readings due to the high pressure. If the leads just change in resistrance due to heat then i'm thinking that I am good to go- accuracy will not be affected since physical not electrial change is likely the onlyu drawback from pushing the probe onto the heatsink with such force.

anyway, i'm just wondering how these temp probes work so I can attempt accurate measurements, would appreciate input on the topic. thanks!
  Reply With Quote
Old 27th September 2005, 03:22 PM   #2
jcx is offline jcx  United States
diyAudio Member
Join Date: Feb 2003
Location: ..
my guess is thermistor - a hi tempco semiconductor based resistor, if so the tiny bead may not like "massive force" as it is a brittle material

in principle force may modify a thermistor resistance but I'd worry first about breaking it, a compliant layer bewteen the sensor and the clamp would be good

Thermistor temp sensors are just ohm-meters with appropriate calibration for particular probe resistance curve -enough ac coupling from a live sink may interfere with their measurement circuitry - a battery powered meter is better because it can "float" at the heat sink potential (safety!)

using a compliant thermal separater/insulator (sil-pad or similar) helps the safety story if your "live" heatsink V is LIVE for safety purposes but no one is going to make a firm recomendation for fear of liability if you fry yourself
  Reply With Quote


Hide this!Advertise here!
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off

Similar Threads
Thread Thread Starter Forum Replies Last Post
Which probes for Tek' 11302? Pengvim Parts 0 8th July 2008 09:45 AM
Tek 465 Probes whubbard Parts 7 12th March 2008 02:20 PM
differencial operation question bobsinclar Pass Labs 31 6th December 2007 10:05 PM
Help getting these d$&* Dynascan probes apart! aletheian Tubes / Valves 2 3rd September 2007 11:52 PM
Differential Probes Jan-Peter Parts 0 25th September 2003 02:19 PM

New To Site? Need Help?

All times are GMT. The time now is 07:44 PM.

vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2017 DragonByte Technologies Ltd.
Copyright 1999-2017 diyAudio

Content Relevant URLs by vBSEO 3.3.2