Temperature sender
Safety Car
Joined: Feb 2006
Posts: 4,142
Likes: 704
Here is a good read on the IR temp scanners: http://www.grainger.com/content/qt-3...d-thermometers
Pro
Joined: Jan 2005
Posts: 644
Likes: 17
From: O'Fallon MO
I bought two sending units, one from Advance Auto and a TU5 from Autozone. Set up a test using a pan of water, a meat thermometer, and a multimeter. This is what I came up with:
Temperature Test (deg. to ohms)
203P (Advance Auto Parts)
100*-0
120*-0
130*-250
140*-232
160*-195
180*-151
190*-135
200*-120
212*-112
TU5 (Autozone)
100*-0
120*-295
130*-272
140*-234
160*-192
180*-162
190*-147
200*-135
212*-112
According to knowledgeable sources, you want 125 to 150 ohms at "normal" operating temp of 180*. The 203P is closer to this number so I chose it, and my gauge still registers about 20 degrees above that. So I added a 10 ohm resister in-line and dropped it to 190. Thinking about adding another 10.
Temperature Test (deg. to ohms)
203P (Advance Auto Parts)
100*-0
120*-0
130*-250
140*-232
160*-195
180*-151
190*-135
200*-120
212*-112
TU5 (Autozone)
100*-0
120*-295
130*-272
140*-234
160*-192
180*-162
190*-147
200*-135
212*-112
According to knowledgeable sources, you want 125 to 150 ohms at "normal" operating temp of 180*. The 203P is closer to this number so I chose it, and my gauge still registers about 20 degrees above that. So I added a 10 ohm resister in-line and dropped it to 190. Thinking about adding another 10.
Mike
1967-L79
Race Director
Joined: Feb 2007
Posts: 15,468
Likes: 8,950
From: northern california
C2 of Year Finalist (track prepared) 2019
Thread sealer is simply a non-issue. IF it was going to have an effect (it doesn't), it would make the gauge read LOW, not high.
