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How to test and adjust a fuel gauge

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Recieved one of Jack's old gauges today and I will play with it and get a setup for testing on this kind of gauge. I have a 0-90 ohm sending unit off soemthing else. I can see how the setup would work with a balancing of resistances, very similar to some of the equipment I worked on in the Airforce. I would think that this type of gauge would be much more accurate than the bimetal kind but much more expensive to manufacture as well.
 
Bi-metal gauges are less prone to "flop around" under the influence of gravity, side-load and impact than the older induction coil ones. Both that and the expense of manufacture were likely responsible for the change-over, IMO.
 
When testing/calibrating the Smiths magnetic gauges (early non-stabilized, non-bimetallic type) there is one point to keep in mind and it's important. Though not spelled out any place I've found, it's important to have the fuel gauge's case grounded to the same ground of the sending unit if you want the instrument to perform properly. An acquaintance of mine in the U.K. didn't think this was... I had to photograph my bench tests and email him the results to prove it. My tests were on the bench and could be illustrated with simple jumper leads. On the car, this indicates that both the gauge and the sender need good clean earth connections.
 
Agree from what I have learned in the last few days here. I don't understand it but agree.

Course I don't understand my gauge either as it shows only 1/8 or so with a preaty full tank even with both wires hooked up and a good ground as tested with a volt meter.
 
Maybe it is pessimistic?

...or has that joke already been made?
 
I think it is just lazy Trevor.
 
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