WIKA 73 Betriebsanleitung Seite 10

7. Alarm contacts
Since the indication must not be affected by the contact mechanism, actuating
forces, and therefore also the possible contact rating, are low.
Sliding contacts are not suitable for liquid-filled instruments!
GB
Magnetic snap-action or sliding contacts are not intrinsically safe and therefore
they are not suitable for applications in potentially explosive atmospheres!
Details see data sheet AC 08.01.
7.2 Inductive alarm sensor Model 831
Inductive alarm sensors are non-contact inductive proximity sensors, which
make or break when a control flag, linked to the measured-value pointer, moves
adjacent to or disengages from the control head (slot-type initiator). Changes in
the signal level will then actuate a control unit (switch amplifier).
Details see data sheet AC 08.01.
7.3 Electronic contact Model 830 E
Direct switching of low-level signals, which are typically used in conjunction with
a PLC, is possible using these inductive alarm contacts, complete with
integrated amplifiers, factory-fitted within the instrument.
The usual advantages of inductive contacts are also valid for this system, such
as highly-secure contact operation, zero wear due to non-contact operation and
virtually no adverse effect on the measuring system, thus ensuring the accuracy
of the indication.
No additional control unit is required.
Electronic contact Model 830 E is not intrinsically safe and therefore not suitable
for applications in potentially explosive atmospheres!
Details see data sheet AC 08.01.
7.4 Electromagnetic compatibility
EMC according to EN 60 947-5-2.
The instruments should be protected against strong electromagnetic fields.
7.5 Contact functions
The contact function of the respective alarm contact is identified by the index 1
or 2 after the model number.
1 = Contact makes when the pointer approaches the set point in clockwise direction
2 = Contact breaks when the pointer approaches the set point in clockwise direction
10 WIKA Operating instructions gas actuated thermometers