Metek DREXELBROOK Universal IV Lite - Page 8

Universal IV - Installation and Operating Instructions
2
Figure 1-1 Capacitance
Sensing Element
k
air
A
d
C
k
media
C
=
k
A
d
C =
k A
d
A
k
air
d
C
k
media
C
=
k
A
d
Tank Wall
Coating
High Resistance
Little to No Resistance
Probe Insulation
Probe Rod
(More Coating is
Easier to Ignore)
R
Xc
Xc
R
Oscillator circuitry through phase shift
cancels small amounts of RF current
flow (both Resistive and Capacitive)
caused by coating
Level
Figure 1-2
RF Admittance Sensing Element
with Cote-Shield