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"Refining" a fuel gauge reading
jimmyd - 1/2/14 at 11:21 AM

Hi All

I'm looking to calibrate the reading on a fuel gauge but retain the existing sender. I assume this is easy enough using a potentiometer and I've a reasonable understanding of the required resistance but no idea of the kinda wattage required. Any advise greatly appreciated!!

J


40inches - 1/2/14 at 12:00 PM

You can buy them. CBS. But they aren't cheap


theprisioner - 1/2/14 at 12:16 PM

Power is calculated V^2/R. Max power in tank and gauge is when the value = gauge resistance usually at empty. If your gauge reads correctly when full (0 ohms) you stand a chane of correcting it as the sense of the sender and gauge are the same. What does the gauge read when empty and what are the respective resistances measured on a digital ohm meter?


chrism - 1/2/14 at 12:31 PM

Can you not adjust it by making the arm on the sender longer or shorter and bending it so it reads out the correct resistance for your gauge.


whitestu - 1/2/14 at 01:39 PM

quote:

Can you not adjust it by making the arm on the sender longer or shorter and bending it so it reads out the correct resistance for your gauge.



+1 - bend the arm until it reads right


40inches - 1/2/14 at 02:04 PM

quote:
Originally posted by chrism
Can you not adjust it by making the arm on the sender longer or shorter and bending it so it reads out the correct resistance for your gauge.


The resistance range in the sender and gauge have to be the same, bending the arm doesn't change the resistance, only the level reading. To get mismatched resistances to read correctly only some form of electronic trickery will work


chrism - 1/2/14 at 05:25 PM

quote:
Originally posted by 40inches
quote:
Originally posted by chrism
Can you not adjust it by making the arm on the sender longer or shorter and bending it so it reads out the correct resistance for your gauge.


The resistance range in the sender and gauge have to be the same, bending the arm doesn't change the resistance, only the level reading. To get mismatched resistances to read correctly only some form of electronic trickery will work


If the resistance levels required by the gauge fall within the levels created by the sender then it would be possible by bending and adjusting the length of the arm to match the swing to the required resistances, if that makes sense, i.e. a longer arm would give a shorter throw from empty to full and a shorter arm would give a longer throw on the sender.


40inches - 1/2/14 at 05:28 PM

quote:
Originally posted by chrism
quote:
Originally posted by 40inches
quote:
Originally posted by chrism
Can you not adjust it by making the arm on the sender longer or shorter and bending it so it reads out the correct resistance for your gauge.


The resistance range in the sender and gauge have to be the same, bending the arm doesn't change the resistance, only the level reading. To get mismatched resistances to read correctly only some form of electronic trickery will work


If the resistance levels required by the gauge fall within the levels created by the sender then it would be possible by bending and adjusting the length of the arm to match the swing to the required resistances, if that makes sense, i.e. a longer arm would give a shorter throw from empty to full and a shorter arm would give a longer throw on the sender.


Ah! That would probably work, using the top and bottom of the tank as stops for the float?


chrism - 1/2/14 at 07:37 PM

quote:
Originally posted by 40inches
quote:
Originally posted by chrism
quote:
Originally posted by 40inches
quote:
Originally posted by chrism
Can you not adjust it by making the arm on the sender longer or shorter and bending it so it reads out the correct resistance for your gauge.


The resistance range in the sender and gauge have to be the same, bending the arm doesn't change the resistance, only the level reading. To get mismatched resistances to read correctly only some form of electronic trickery will work


If the resistance levels required by the gauge fall within the levels created by the sender then it would be possible by bending and adjusting the length of the arm to match the swing to the required resistances, if that makes sense, i.e. a longer arm would give a shorter throw from empty to full and a shorter arm would give a longer throw on the sender.


Ah! That would probably work, using the top and bottom of the tank as stops for the float?


Yes, just relies on the sender being in about the right range and resistance going in the right direction for the sender.