7ML19985GE04
SITRANS LC500 – OPERATING INSTRUCTIONS
Page 17
P
robe Configur
at
io
n
Probe Configuration
The probe (electrode) comprises a measurement section and an active shield section.
This electrode connects to the capacitance detector portion of the two-wire loop
powered electronic transmitter. The transmitter module is mounted in a powder-coated
aluminum enclosure which provides reliable operation in environments with dust,
moisture, and high-frequency interference.
SITRANS LC500 Electrode (Probe) Characteristics
Apply to all general connection configurations:
•
The standard SITRANS LC500 insulated electrode is designed for use in both
conducting and non-conducting liquid applications.
•
Most electrodes consist of an active shield portion and a measurement portion,
which combine to form the complete electrode. (This is not the case for cable
electrodes or electrodes with ceramic/enamel insulation.)
•
The sum of the active shield length and the measurement length is the total
insertion length.
•
The active shield design provides continuous immunity from changes in conditions
at the top of the vessel where levels of vapors, dust, and condensation may be
constantly changing.
•
The design of the active shield isolates the starting capacitance of the electrode
from the effects of changes in capacitance due to temperature and pressure
fluctuations that could cause small changes in the seal geometry.
•
The carefully-controlled diameter of the electrodes and insulation produces a linear
output over a wide range of capacitance values (1 pF to 3300 pF).
•
The end seal is formed as an integral part of the electrode insulation, giving smooth
and uniform characteristics (tested to 55 kV).
•
Standard single cone seal
insertion length
active
shield
measure-
ment
portion
probe
seal
(inactive)