Solve Water Level Sensor Problem w/Capacitance-Based Sensors

[vuongd]

i am having trouble with a problem about a capacitor based sensor.. i am to propose two separate capacitance based sensors, one for soil moisture and another for water level..

my problem is finding the time constant inorder to find C

so i can use the equation C = k(e0)A/d to solve for k... as i would know C, A and d in my proposed system

i know that C= T/R my R will be know except T which i can find... i know i can get T with a frequency meter device, but because i have little knowledge of what it is, i have no idea where i would place this device onto my capacitor circuit... (which is where my problem lies) how would i place a frequency meter into a simple RC circuit?

im not sure if I am on the right track, any help would be much appreciated

 

[NoTime]

Your question isn't entirely clear.
In order to use a frequency counter here, it would have to be capable of measuring an interval.
Not a standard feature on frequency counters.

Usually, C would be part of an oscillator circuit.