JUMO 60.8425 Contact dial thermometer with inductive contact Operating Manual - Handbuch (Seite 17)

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1.2 Description
Dial thermometers with rigid stem or capillary are filled either with an organic
liquid or with gas, and operate on the principle of liquid expansion or pressure
change. The resulting movement is converted into a rotation of the pointer,
without any mechanical gearing.
The inductive limit contact is operated by a contactless proximity switch. The
sensor is a slot-type initiator attached to the setpoint indicator. The control flag
is activated by the pointer.
If the control flag moves into the sensor gap, the internal resistance increases
(active area damped, high-resistance initiator – relay de-energized). The
switching amplifier of the control device responds to the resulting change in
current.
Provided you observe the instructions below, you can be sure of problem-free
operation.
1.3 Regulations and notes
Accessories The necessary accessories are inside a bag that is enclosed with the
thermometer. Please check the package carefully!
H
Contact dial thermometers with inductive contacts may be used in potentially
explosive atmospheres (zone 1) if they are fed from certified intrinsically safe
circuits.
For electrical data and temperature limits, see EC-Type-Examination
Certificate PTB 99 ATEX 2219 X in the appendix.
V
With dangerous measurement media such as oxygen, acetylene, flammable
and toxic substances, as well as in refrigeration equipment, pressure vessels
etc., the relevant regulations and requirements must be observed.
1 Introduction