Calibrating temp sender

[tvrgeek]

OK, got my sender from Rimmer. It has a black insulator if that means anything. At 68 F, it reads 920 Ohms. @ 185, it reads 65 Ohms.

Now, my gauge had an add-on resister on the back. Clearly OEM, not a hack. Gauge reads 61 Ohms @ 68F. Resister is 14 Ohms.

With the resister, boiling, I read just past the center mark. Without it, gauge reads right on the third tick mark. Without, 185 was pretty close to centered. So, with THIS sender, I want no resister. Bench test, regulated 10V supply and I will be using a solid state stabilizer.

Clock fixed, temp gauge fixed. Voltmeter good. Speedo cable on order. Tach good. Now to test/calibrate the new tank sender.

[Phil S]

but remember the boiling point of water is raised by approx 1 deg per 1psi pressure in the radiator, not that will alter your gauge calibration

[tvrgeek]

Of course. but SOP is to have the gauge mid-range when things are as expected. Third tick for boiling is pretty good as it is telling you are no longer within control range. So by the time it gets to red, it is time to be pulling over/

[DJT]

http://www.ldpart.co.uk/shop/shop.php?c=viewproduct&pid=191&cat=3&sid=sid9f9dddbf1b2892e4765108208cdd2e5d

[tvrgeek]

So LD's part, ( out of stock) gives mid point @ 195F, where the one from Rimmer gave it @ 185. So depending on which thermostat, you are centered or just above, but still the third tick @ 212 or so is a warning you are no longer under control and by the time yo hot red, you may be boiling over.

[DJT]

So LD's part, ( out of stock) gives mid point @ 195F, where the one from Rimmer gave it @ 185. So depending on which thermostat, you are centered or just above, but still the third tick @ 212 or so is a warning you are no longer under control and by the time yo hot red, you may be boiling over.

I’ve been running the LDPart sender for many years with an 88 degree thermostat. OE fan and viscous coupling. Needle sits just left of vertical and only reaches vertical on the hottest of days and the backup Kenlowe fan never kicks in.

[trunt]

The smiths gauges have calibration marks on the face, they also have adjusters for hi and lo. I recall seeing some info on a calibration routine where a specific voltage is fed to the gauge and it is adjusted to the marks. I never got a firm idea of exactly what the voltages were for all types of gauge or weather they were all the same.

eg

https://www.triumphexp.com/forum/triumph-odds-and-ends-forum.9/calibration-of-smiths-temperature-and-fuel.1405143/

anyone come across that info?

Terry