hi everyone
I'm about to design a capacitive soil moisture sensor.
I have to make a capacitor on my PCB whose value will change by the change in dielectric, in my case water will effect the dielectric of soil and therefore the value of capacity will change as well.
take a look at this PCB layout which form coplanar capacity
check this link for a sample of coplanar capacitor PCB as a Capacitive Soil Moisture Sensor
my question is: will really having plates on both sides of PCB give us wider sense of water(moisture)?
here I explain why I think it wont:
I made up my own type of capacitor using straight wires held on ruler to keep them well separated in equal distance along.
I used this as my soil moisture capacitor and it did a good job.
then I thought: why not increase the level of water even more? using an other pair of wire on back side?
so I did that too but the result didn't change...
here is a funny thing: both pair wires show equal capacity, but I expect having them both parallel in circuit will give me value 2 times of one pair.
why is that?
I'm about to design a capacitive soil moisture sensor.
I have to make a capacitor on my PCB whose value will change by the change in dielectric, in my case water will effect the dielectric of soil and therefore the value of capacity will change as well.
take a look at this PCB layout which form coplanar capacity
check this link for a sample of coplanar capacitor PCB as a Capacitive Soil Moisture Sensor
my question is: will really having plates on both sides of PCB give us wider sense of water(moisture)?
here I explain why I think it wont:
I made up my own type of capacitor using straight wires held on ruler to keep them well separated in equal distance along.
I used this as my soil moisture capacitor and it did a good job.
then I thought: why not increase the level of water even more? using an other pair of wire on back side?
so I did that too but the result didn't change...
here is a funny thing: both pair wires show equal capacity, but I expect having them both parallel in circuit will give me value 2 times of one pair.
why is that?