Using multiple AD7746 for liquid level sensing

I am designing a liquid level sensing application with the following requirements:

- between PCB (sensor) and liquid, there is 1.5mm plastic, 0.5mm air, and 2.5mm plastic (the latter could be adjusted down)

- I need it to be precise and repeatable

- liquid and electronic are both floating (battery)

- height of container is 200mm

- desired resolution is about 5mm

Instead of having two sensor strips spanning the full height of the sensor, I thought it would be more noise resistant, and generally better to split the sensors in multiple smaller sensors.

I plan to stack up to 8 AD7746 on my sensor baord, for a total of 16 smaller sensor.

I will put a transistor on each chip VDD and have them ON one by one to avoid interference and I2C address collision.

My questions are:

- do you have any reference design, or design tips regarding the segmented sensor approach?

- any recommendation of sensor layout and size?

- any remark or general tips?

- recommendation on what component to use? I mentioned 8 AD7746, but I could also use like 2 AD7147.



Added note about AD7147
[edited by: kuon at 4:08 AM (GMT -5) on 19 Feb 2021]
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