I need to build a humidity sensing circuit that feeds an analogue to digital converter. (This converter is then going to send its signals to a raspberry pi for analysis etc). The sensor will be about 0.5m away from the amplifier circuit (As it will be inside a climate cabinet, and the circuitry will be outside) and I have seen in my research that having a distance between the circuits causes further complications.
I have found a capacitive humidity sensor that fits my temperature range needs (IST MK33). This has a range of capacitance of approx 290pF to 340pF (showing 0% relative humidity through to 100%). I need to then convert this somehow into a suitable input for an MCP3008 ADC, I'm assuming a range of 0v-5v will work. This will then communicate via SPI to the Raspberry Pi.
I have a 24VDC supply originally but I shall also have 5V, and 3.3VDC supplies available to drive this circuit because of the raspberry pi. I looked at the circuit and answers in this question: Converting variable capacitance value to variable DC voltage level but what with the difference in the range of the capacitance value I wondered if this is still suitable?
So my question is: is the circuit in the above link still suitable? or can someone suggest a different circuit with suitable values that would work? I'm very new to all this so I've been struggling and the data sheet for the sensor hasn't got any example circuits, which normally save me! Thanks in advance. :)