How to test unknown fuel gauge.

I understand how to test the three senders, gas, oil, temp. Being able to test the accuracy of the gauge out of the car would be great. I'll start- the source voltage would have to be 4 volts. The sender side of the gauge would need three options- 74 ohms, 23 ohms and 10 ohms. To adjust accuracy you bend the needle. How am I doing so far?