2
1.3.
Risks of Disregarding Safety Instructions
Disregarding safety instructions, use of this product for
purposes for which it is not intended, and/or operation of
this product outside the limits specified for any of its tech-
nical parameters, can result in harm to persons, the en-
vironment, or the plant on which it is installed. Fischer
Mess- und Regeltechnik GmbH will not be responsible
for consequences in such circumstances.
1.4.
Safety Instructions for Operators
Safety instructions for the proper use of this product must
be followed. This information must be available at all
times by personnel responsible for installation, operation,
maintenance and inspection of this product. Adequate
steps must be taken to prevent the occurrence of hazar-
dous conditions that can be caused by electric energy
and the convertible energy of the process media. Such
conditions can, for example, be the result of improper
electrical or process connections. Detailed information is
available in relevant published norms (DIN EN, UVW in
Germany; and equivalents in other countries), industrial
standards such as DVWG, Ex-, GL-, VDE guidelines, as
well as regulations of the local authorities (e.g., EVUs in
Germany).
The instrument must be put out of action and protected
against accidental use if safe operation can not be gua-
ranteed anymore. A reason for this might be one of the
following incidents:
apparent damage of instrument
failure of electrical function
bad packaging during transport
Repairing is only allowed to be done by Fischer Mess-
und Regeltechnik GmbH.
Before the instrument is put into operation again a pro-
fessional routine test acc. to DIN EN61010, part 1 needs
to be done. This inspection should necessarily be done
by Fischer Mess- und Regeltechnik GmbH. Appropiate
transport and professional storage of instrument are un-
derstood.
1.5.
Modifications Forbidden
Modification or other technical alteration of the product is
not permissible. This also applies to the use of unautho-
rized spare parts for repair / maintenance of the product.
Any modifications to this product, if and as necessary,
should be done only by Fischer Mess- und Regeltechnik
GmbH.
1.6.
Operational Restrictions
The operational reliability of the product is guaranteed
only when used for intended purposes. The product must
be selected and configured for use specifically with defi-
ned process media. The limiting values of operating pa-
rameters, as given in the product specification sheet,
must never be crossed.
1.7.
Safety Considerations during Installation and
Maintenance
The safety instructions given in this manual, existing na-
tional regulations relating to accident prevention, and the
internal safety rules and procedures of the user organi-
zation regarding safety during installation, operation and
servicing must all be followed meticulously.
It is the responsibility of the users to ensure that only sui-
tably qualified and experienced technical personnel are
used for installation, operation and servicing of this
equipment.
2.
Intended Applications
Display and limit detection of differential pressure of ga-
ses. The product must be used only for applications and
under conditions specified by the manufacturer.
Classification of Explosion-Hazardous Area
2-Channel Differential Pressure Switch / Transmitter
DE44 is suitable as „electrical equipment for use in ex-
plosion-hazardous areas (flammable gas), zone 2.
Declaration per Directive 94/9/EC (ATEX)
-10°C T
amb
60°C
3.
Product Description and Functions
3.1.
Functional Scheme
3.2.
Principles of Operation
The instrument is based on dual piezo-resistive sensor
elements, each of which can measure positive gauge,
negative gauge (vacuum) or differential pressure. The
pressure is measured directly by a piezo-resistive resi-
stance bridge that is formed on the surface of an integral
silicon diaphragm in each sensor. Change of pressure
results in change of resistance that is converted to a va-
rying voltage and then digitized. The instrument's internal
microcontroller transfers the measured value on the LED
display, controls the two limit detection switches, and op-
tionally transmits the measured value through an ana-
logue conversion stage as a voltage or current signal
output. The output of sensor 1 is used by limit switch 1
Contact: EK Engineering (India)
Web: www.ekeindia.com
Email: [email protected]
