I have in my oil tank a sensor rod (PCB) and being reasonably proficient in electronics have interested in designing a "reader" for the device. It has 6 terminals at the end of the PCB, 2 of which appear to be common. Resistance measurements of the 4 sensors are inconclusive. I suspect that the sensors are capacitive and probably vary the frequency of an oscillator according to oil level. Has anyone any ideas (or a circuit schematic). I know that I can buy one but that's no fun and expensive.
TIA
TIA
