The appropriate national safety regulations (e.g. EN 837-2
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„Selection and installation recommendations for pressure
gauges“) must be ob-served when installing, commissioning and operating these devices.
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Serious injuries and/or damage may occur should the appropriate
regulations not be observed.
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Only appropriately qualied personnel should work on these
instruments.
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The eective maximum surface temperature is not dependant upon
the device, but mainly on the temperature of the respective pressure medium! In the case of gaseous substances, the temperature
may increase due to compression warming. In these cases it may
be necessary to throttle the rate of change of pressure or reduce
the permissible temperature of the pressure medium.
2. Operating principle
Bourdon tubes are widely used as measuring elements for technical
pressure measurement due to their robustness and ease-of-use. Under
the inuence of pressure these measuring elements will deform within their
elastic range.
This movement is converted into a rotary motion by means of a mechanical
movement (gear). A magnet, xed to the pointer axle, turns with the
instrument´s pointer in direct proportion to the process pressure. The
electronics positioned facing the magnet detect the rotational motion of the
magnet.
The electronics’ non-contact sensor element (Hall sensor), aected by the
magnetic eld, detects any changes, free from any friction and wear to the
measuring element.
The sensor signal, which is in direct proportion to the angle of motion, is
transformed into an output signal. The span of the electrical output signal
corresponds to the measuring span of the dial.
An intelliGAUGE line pressure gauge with electrical output signal combines
all the advantages of an on-site display without the need for an external
power supply, with the demands of modern electronic measurement for
electrical signal transmission.
Nominal position acc. EN 873-3 / 9.6.6 gure 7: 0° or 90°
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Pressure connector bottom or rearside
Permissible vibration load at the mounting point
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The instrument should always be installed in locations free of vibration.
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If necessary, it is possible to isolate the instrument from the mounting
point by installing a exible connection line between the measuring
point and the pressure gauge and mounting the instrument on a suitable
bracket.
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If this is not possible, the following limit values must not be exceeded:
Unlled devices: Frequency range 10 … 150 Hz
Accelaration < 0.5 g (5.0 m/s²)
Liquid lled devices: Frequency range 10 … 150 Hz
Accelaration < 4.0 g (39.2 m/s²)
The liquid lling has to be checked periodically.
The liquid level must not drop below 75 % of the instrument´s diameter.
Test connector
At certain use cases (e.g. steam vessels) isolating devices have to have a
test connector, so that the instrument can be checked without dismounting.
Mounting provisions
If the line for the pressure gauge is not rigid enough for vibration-free installation, fasten the instrument using appropriate fastening elements for wall
and / or pipe mounting, and, if necessary, by means of a capillary line.
Measuring system damping
If it is not possible to avoid vibration by means of appropriate mounting, use
pressure gauges with liquid lling.
Eects of temperature
The mounting of the pressure instrument has to be done in a way that the
operating temperature is neither exceeded nor falls below the permissible
operating temperature, even in consideration of thermal convection and
thermal radiation. Tailpipes of a suitable length or syphons may be used to
protect the pressure instrument and the isolating device.
The inuence of the temperature onto the accuracy of indication and of
3. Installation instructions / 4. Installation and ...
Diaphragm seal / protective barrier
In case of aggressive, hot, highly viscous, contaminated or crystallizing
pressure media, which must not be allowed to intrude the measurign
element, diaphragm seals have to be used as separating barrier. A neutral
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transmission uid, used to transmit the pressure to the measuring element,
should be selected in consideration of the measuring range, the temperature and its compatibility with the pressure media.
The connection between the pressure gauge and the diaphragm seal must
not be released by no means.
Protection of the measuring element against overload
If the pressure media is subject to rapid pressure changes or pressure
impulses may be expected, these must not act directly upon the measuring
element. The eect of pressure impulses must be damped, e.g. by installing
an integrated restrictor screw (reduction of the cross section in the pressure
channel) or by connecting an adjustable throttle device in series.
Pressure test connection
The pressure test connection, with a suciently large bore size (≥ 6 mm
diameter), should be arranged, as far as possible, over a shut-o device,
in a position where the accuracy of the reading will not be aected by the
ow of the media being measured. The pipe between the pressure test
connection and the pressure instrument should have an inner diameter
large enough to avoid blockages or delays in pressure transmission. Also it
should not have any sharp bends. It is recommended that it is mounted with
a steep incline of approx. 1:15.
Piping
The piping should be arranged and tted so that it can withstand the
stresses caused by expansion, vibration and the inuence of heat. When
the media is gaseous, a water drain point should be provided at the lowest
point. For liquid pressure media, an air bleed should be provided at the
highest point.
4. Installation and commissioning
To acchieve a correct sealing of pressure connections suitable sealing
rings, sealing washers or WIKA prole seals have to be used. In order to get
the pressure instrument into an orientation that allows to read the on-site
indicator the best, a connector with an adjusting nut or an union nut is
recommended. When mounting and dismounting it is not allowed to tighten
the pressure instruments by using the housing, but on the spanner ats of
4. Installation and commissioning / 5. Measuring arrangements
Installation using
a spanner
If the pressure transmitter is positioned lower than the pressure test
connection, the tailpipe has to be rinsed thoroughly prior to tting the gauge
to remove all foreign substances.
Once the pressure and electrical connections have been made, the trans-
mitter is ready for immediate use.
Before dismounting the pressure instrument the measuring element has to
be depressurized. Eventually the stress of the pipe has to be relieved.
Residual pressure medium remaining within the pressure
element may cause harm to men, facilities and environment.
Therefore sucient precautionary measures have to be
taken.
Pressure connector
In accordance with the general technical regulations for pressure gauges
(e.g. EN 837-2 „Selection and installation recommendations for pressure
gauges“).
5. Measuring arrangements
Proven measuring arrangements for various types of media.
The electrical connection of pressure gauges with an electrical output
/ electronic pressure switch is made via a plug or a cable. The correct
signal
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terminal connections can be seen in the table below.
Additionally the terminal assignment, output signal and necessary supply
voltage are written on the product label.
3-pin connector, model AMP Duoplug
Pin Signal
1 U
2 GND
3 U
Cable (2-wire)
Colour code Signal
black GND
red U
Cable (3-wire / 1 x NPN)
Colour code Signal
black GND
red U
orange U
Cable (4-wire / 2 x NPN)
Colour code Signal
black GND
red U
orange SP
brown SP