Electric Gauge

[Richard71]

Can anyone tell me how to "bench test" an electric Smiths oil pressure gauge without causing any damage?

 

Richard.

[Waldi]

Maybe you can test the combination of sensor and gauge, this also shows any incompatibility of the two (or combined result).

Test against a reasonable quality pressure gauge, like from an air compressor.

Hope this helps.

Waldi

[john.r.davies]

What do you want to test?

That it works at all - connect a nine volt battery (P9) across it, briefly, and see the needle head for a high pressure.

Or, calibrate it, in which case wot he sed.

 

John

[RobH]

It appears that the Smiths electrical oil pressure sender is 150 Ohms at zero and about 20 Ohms at full-scale (which is the opposite way round to modern ones). You could test the gauge by powering it from a 9v battery as John says, and connecting a suitable value resistor to earth instead of the sender. 150 Ohm for 0, 20 Ohm for full scale and aboout 62 Ohms for half-way. That isn't a calibration but it will tell you whether the gauge is roughly right.

[Richard71]

What do you want to test?

That it works at all - connect a nine volt battery (P9) across it, briefly, and see the needle head for a high pressure.

Or, calibrate it, in which case wot he sed.

 

John

 

Sorry Fellas,

I should have been more specific, just want to check the needle move and will do as John advises..

 

Many thanks.

 

P.S.

 

Any drawing I've seen for the electrical oil pressure gauge shows that it requires 12v feed and not the 10v-ish via the stabiliser.

Is that correct?

 

Richard.

[john.r.davies]

Triumph used the "stabiliser" (in fact it alternates 12 and 0 volts, to average 10v) as otherwise volts variation due to charging and/or current use would affect the reading. But I think they always used gauges directly connected to the oilways. If this is a modern gauge, do as the instructions say!

John