K
Klaus Kragelund
- Jan 1, 1970
- 0
Hi
I'm working on a water sensor
The application is a pump which has a metallic surface connected to
the
earth wire. The sensor consists of a metal plate housed in a plastic
enclousure mounted on the chassis of the pump. The capacitance
measured
is the one from the metal plate to the chassis - growing in value
when
the water is present. The sensor plate is in direct contact with the
water
So with pure or low contaminated water we measure the capacitance
between the electrodes taking advantage of the dielectric constant of
80 for water.
When the water is polluted or is a salt solution we measure the
conductance of the water
But, I'm searching for theory/documentation for the conductance of
water with a salt solution at different frequencies. I have measured
the conductance using a network analyzer and have found that it seems
the conductance is lower at higher frequencies. So it seems at very
high frequencies (300MHz) the water begins to act as a capacitance
again without significant conductance.
But I want to be sure and don't want to measure all kinds of extremes.
So does anyone know of theory/books/links to descriptions of the
properties of water? (conductance, dielectric value etc)
Thanks
Klaus
I'm working on a water sensor
The application is a pump which has a metallic surface connected to
the
earth wire. The sensor consists of a metal plate housed in a plastic
enclousure mounted on the chassis of the pump. The capacitance
measured
is the one from the metal plate to the chassis - growing in value
when
the water is present. The sensor plate is in direct contact with the
water
So with pure or low contaminated water we measure the capacitance
between the electrodes taking advantage of the dielectric constant of
80 for water.
When the water is polluted or is a salt solution we measure the
conductance of the water
But, I'm searching for theory/documentation for the conductance of
water with a salt solution at different frequencies. I have measured
the conductance using a network analyzer and have found that it seems
the conductance is lower at higher frequencies. So it seems at very
high frequencies (300MHz) the water begins to act as a capacitance
again without significant conductance.
But I want to be sure and don't want to measure all kinds of extremes.
So does anyone know of theory/books/links to descriptions of the
properties of water? (conductance, dielectric value etc)
Thanks
Klaus