Design And Measuring Principle - bürkert 8225 Bedienungsanleitung

2 SPECIFICATION

2.2 Design and Measuring Principle

Design
The compact conductivity transmitter
combines a sensor and a transducer with
display in a splash-proof plastic IP65
enclosure.
The sensor component consists of easily
replaceable sensors. Sensors with cell
constants of 0.01 and 0.1 are fitted with
stainless steel electrodes, and those with a
higher cell constant 1.0 and 10 are fitted
with graphite electrodes. The Pt1000 for
automatic temperature compensation is a
standard feature in all sensor housings.
The transducer component converts the
measured signal and displays the actual
value.
The output signal is provided within a 4-
pole plug according to DIN 43 650 or via
one PG 13.5 (version without relays) or via
2 PG 13.5 (version with relays).
8225-COMP-**
CONDUCTIVITY 8225
Measuring Principle
Conductivity is defined as the ability of a
solution to conduct electrical current. The
load carriers are ions (e.g. dissolved salts
or acids). In order to measure the
conductivity, 2 electrodes are used which
are set at a fixed distance apart and with a
known specified surface. An AC voltage
source is connected to the electrodes. The
measured current is a direct function of the
conductivity of the solution.
The transducer without relays functions has
a 2-wire circuit and requires a power supply
of 12...30 VDC. The decice is avaulable with
an integrated power supply of 115/230 VAC.
A standard output signal of 4...20 mA is
available, altthough it is proportional to the
conductivity.
The transducer with 2 additional relays
functions has a 3-wire circuit. Limit values
are freely adjustable.
E-5-