Pressure Correction - Siemens ULTRAMAT 6F Operating Instructions Manual

5.3 Additional measures for devices in hazardous areas
The analyzers may only be used in hazardous areas if all required gas inlet and outlet lines have been connected prior to
startup and tested for leaks and tightness with 1.5 times the respective maximum permissible operating pressure.
The operator is responsible for the required gas inlet and outlet lines. These must also correspond to the requirements for
"Pressurized enclosure" explosion protection type and must be tested separately in accordance with EN 60079-2.
5.3.1 Ex px safety equipment
Prerequisite
● You operate the analyzer in one of the following Ex protection types:
– Pressurized enclosure with leakage compensation for Zone 1 in accordance with certificate PTB 00 ATEX 2022 X
– Pressurized enclosure with continuous purging for Zone 1 in accordance with certificate TÜV 01 ATEX 1708 X
● You have connected the analyzer to the Ex px safety equipment according to the connection diagrams in section
Connection diagrams (Page 23).
Prior to startup, you must still:
● Check the supply voltage
● Close all unused cable glands with the supplied plugs.
● Carefully screw down the used cable glands.
● Close the doors. You must tighten the screws evenly until the door frame touches the enclosure surface.
● Set the upstream pressure of the protective gas (it should be 0.2 ... 0.4 MPa upstream of pressure regulator).
● Set the pressure regulator of the Ex px safety equipment to at least 0.2 MPa.
When measuring combustible gases with Ex px protection rating with leakage compensation, you must ensure that the
sample gas pressure applied to the analyzer is not more than 164 hPa (164 mbar) above the atmospheric pressure and is
always at least 50 Pa (recommended 5 hPa) below the protective gas pressure.
If this condition cannot be guaranteed at all times, you must fit a differential pressure monitor between the sample gas and
purging gas as additional protection.
After carrying out the measures described above, you can start up the analyzer by
1. Opening the protective gas path and
2. Switching on the supply voltage
5.3.2

Pressure correction

There is an internal pressure sensor in the ULTRAMAT 6F for correcting the influence of atmospheric pressure. This is
connected to the ambient air by a pipe. To avoid explosive atmosphere diffusing into the pressure sensor, this pipe must be
connected to a hose which ends in the non-hazardous area.
A higher sample gas pressure up to 1500 hPa can only be measured with an external pressure sensor. Its signal must be
fed into the analyzer in an intrinsically-safe manner. Its parts wetted by the sample gas must meet the requirements of the
measurement. Connection and parameterization of an external pressure sensor are described in the associated Operating
Instructions.
In the OXYMAT 6F the influence of the sample gas pressure can be corrected by the internal pressure sensor in a range up
to 2000 hPa. A higher pressure up to approx. 3000 hPa can only be measured with an external absolute pressure sensor.
The CALOMAT 6F/CALOMAT 62F is largely independent of the input pressure as a result of its measuring procedure
(thermal conductivity). It may nevertheless be necessary to compensate the influence of pressure using an external pressure
sensor. An external pressure sensor is also required if the input pressure is greater than 1100 hPa absolute.
Note
Using external pressure sensors
If an external pressure sensor is used, the internal pressure sensor must be sealed if it is not connected to the non-
hazardous area.
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Compact Operating Instructions in accordance with EN 61010-1 and EN 60079-0
A5E45779389002-01, 09/2018