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# TPS & temperature

## 4 posts in this topic

After searching the posts and finding no answer, I would like to know if anyone has an idea how temperature affects the resistance values given in the manual for the TPS.

We don't all live in perfect California, and here on the right coast, my garage is a balmy 35 degrees under the reference temperature.

John

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Wire Gauge Resistance per foot of wire @ 70 degrees F:

10 Gauge 0.00118

12 Gauge 0.00187

14 Gauge 0.00297

16 Gauge 0.00473

18 Gauge 0.00751

20 Gauge 0.0119

22 Gauge 0.0190

24 Gauge 0.0302

26 Gauge 0.0480

28 Gauge 0.0764

Copper wire has a resistivity coefficient of 0.0039 per degree C or 0.00216 per degree F.

So the resistance change is calculated by the measured resistance at a specific temperature with respect to the observed temperature:

The new reisitance at temp T is calculated with the following simple formula where R is the measured or calculated resistance by feet of wire and gauge at 70 degrees:

R (at T) = R (at 70F) x ( 1 + 0.00216 x (T - 70F)

Therefore a 50 degree temperature swing from room temperature will change the copper wire resistance by 10.8 percent higher ( if riding in 120F desert) or lower ( if riding in freezing 0F Alaska)

Hope that helps.

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I knew there would be someone with a technical mind to help!

So, in essence, about 5% difference (lower in resistance) for about thirty degrees under the spec temperature? Or, a negligible effect?

John

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You got it John! About 6% change for 30 degrees.