M&C TechGroup PMA 50 EEX Operator's manual - Manual (Page 32)

32
Gas sampling and gas conditioning technology 9-3.15-ME

Pull off the green 2-, 3- and 4-pole plug-in connections from the power supply board;

Loosen the earth connection (green-yellow) of the transmitter unit (3 see figure.6);

Loosen the hex screws 4 (see figure 6) on the top of the transmitter mounting plate;

Loosen union nuts 1 at sample in- and outlet 7 (see figure 6);

Now, the complete transmitter unit can be taken out of the housing. All further procedures should be
executed on a clean work bench outside the hazardous area. Put the transmitter unit in a position as
shown in figure 7 (18-pole plug must show to the right side).

Electrical connections meas. cell

Heater element

Gas outlet measuring cell

Transmitter board

Gas inlet measuring cell

Temperature cut out at 72 O C

Fastening screw for measuring cell

Temperature sensor
Figure 7 Transmitter unit

Unsolder the brown and yellow cable from the terminals 1 (see figure 7) on the back side of the
measuring cell; do not overheat the terminals; mark the cables accordingly;

Disconnect the tubing for the sample gas outlet 2 and sample gas inlet 3;

Loosen the fastening screw of the measuring cell 4 with a screw driver and pick carefully the cell;

Exchange only with measuring cells of the same type;

Turn the transmitter as shown in figure 8 and loosen the fastening screw of the photocell 4.
The mountage of the measuring cell is to be effected in reverse order; take care of the correct dumpbell
position!
In case there are minimally different positions of the dumpbells inside the measuring cells when
mounting a new cell, it is absolutely necessary to adjust the zero point mechanically.