Series Land Rovers
Temperature Sender Voltages
Have one of those modern senders for the temperature gauge that uses wire rather than a capilary tube? Curious to pass some time away with a volt meter to check operation?
Well the equation for resistance versus Temperature is R = a + (b * exp(c * (Te mp + d))) where R is in ohms, T is in degrees Celsius a = 5 ohms b = 4.4 ohms c = -0.035 (units are inverse degrees Celsius) d = -172 degrees Celcius exp is the exponential function , i.e. e to the power of, where e is 2.718281828.
What this allows you to do is to callibrate a guage which does not have the temperature marked on it. An example -
indication resistance temperature (from formula)
| 0% |
196 ohms |
64 degrees C |
| 25 |
93 |
84 |
| 50 |
54 |
103 |
| 75 |
43 |
111 |
| 100 |
16 |
144 |
The accuracy of this calibration is about +/- 2 degrees C.
Reprinted from the OVLR Newsletter, November 1997 |
