Introduction; System Description; Technology - Ametek IntelliPoint RF RML Series Installation And Operating Instructions Manual

IntelliPoint RF RML Series
Section 1: Introduction
1.1

System Description

1.2

Technology

k
d d
A A
k
k
C C
air
k
media
k A
k A
C =
C =
d
Figure 1-1
Simple Capacitance
Probe
Figure 1-2
RF Admittance Probe
with Cote-Shield
The AMETEK Drexelbrook, IntelliPoint RML and RGL
Series point level switches detect the presence or absence
of material and provide a relay output for control functions.
The RML and RGL IntelliPoint switches are calibrated
through a simple potentiometer adjustment.
Since the IntelliPoint RML Series requires calibration and
setpoint adjustments, it is not capable of operating in non-
dedicated tanks.
In a simple capacitance probe-type sensing element,
when the level rises and material covers the probe, the
capacitance within the circuit between the probe and the
media (conductive applications), or the probe and the vessel
wall (insulating applications), increases. This is due to
the dielectric constant (k) of the material which causes a
bridge imbalance. The signal is demodulated (rectified)
air
and amplified, then the output is increased. There are
drawbacks, however, especially when there is coating of the
probe.
media
An RF Admittance level transmitter is the next generation.
Although similar to the capacitance concept, IntelliPoint
employs a radio frequency signal and adds the Cote-Shield
d
circuitry within the Electronics Unit. This patented Cote-
Shield circuitry is designed into the IntelliPoint series and
enables the instrument to ignore the effect of buildup, that
is, material coating on the sensing element. The sensing
element is mounted in the vessel and provides a change
in RF admittance indicating the presence or absence of
material.
The Cote-Shield element of the sensor prevents the
transmission of RF current through the coating on the
sensing element. The only path to ground available for the
RF current is through the material being measured.
The result is an accurate measurement regardless of the
amount of coating on the probe, making it the most versatile
technology available by far. Not only does it work with all
types of materials, it's well suited to a very broad range
of conditions, from cryogenics to high temperature, from
vacuum all the way to 10,000psi
pressure.
1

Introduction