KROHNE UFM 500 EN - Manual (Page 33)

33
Part C Special applications, functional checks and service
6. Special applications
6.1 Use in hazardous areas
The ALTOSONIC UFM 500 K-Ex ultrasonic flowmeter
is certified to European Standard as an electrical
appliance suitable for use in hazardous areas.
Allocation of temperature class to temperature of the
fluid, meter size and material of the measuring tube liner
is specified in the test certificate.
Test certificate, certificate of conformity and wiring
instructions are attached to the Installation and
Operating Instructions (applies only to hazardous-
duty equipment).
6.2 Empty measuring tube
When the measuring tube is empty, the two outputs and
the display will go to “zero” or to the set minimum
values, as for “zero” flow.
This means
Display
→
0
Current output
→
0 or 4 mA
or value of I
0%
(see fct. 3.3.3)
Frequency output
→
0 Volt (= no pulses)
With the UFC 500... signal converter, the error EMPTY
PIPE then appears in the Error List in the “Quit./Reset
menu”, see sect. 4.4, and the compass field shows a
steady light.
6.3 High-temperature version (>180
°
C/>356
°
F)
The ALTOSONIC UFM 500 F flowmeter is also
available as a special version for process temperatures in
excess of 180°C/356°F. Special supplementary
installation instructions are supplied with these systems.
6.4 Magnetic sensors, setting with hand-held bar
magnet
•
The UFC 500... signal converter can optionally be
equipped with magnetic sensors, see sect. 4.1, Item 5.
•
This allows setting of the signal converter by means
of a hand-held bar magnet. Function of sensors
without removing the front cover is the same as the
corresponding keys. Sensor response is acknowledged
by symbols in the 1
st
line of the display.
•
Hold the bar magnet by the rubber cap. Apply the end
of the magnet (North Pole) to the glass pane above
the magnetic sensors.