MSA SUPREMA - Page 171

REV 0, June 2005 Page 171
Operation Manual SUPREMA
6. Startup
Person 1:
• Connect the digital multimeter to the test sockets on the MAI module (red/black) and
select the 3 V DC measuring range.
• Press the MS button to select the input. Each press of the button advances the input
by one in sequence. The selected input is indicated by the forward row of LEDs (LED at
the top = input 1, LED at the bottom = input 8). The LED of the selected input lights up
green.
• Enable operator buttons (UP, DOWN, MS) by pressing the SEL-Button.
Person 2:
• Supply the zero gas to the sensor corresponding to the selected input (for about 5
minutes or in accordance with the sensor O&M instructions) at least until person 1 has
completed the preliminary adjustment of the zero point.
Person 1:
• Using the SEL button, select the function ZERO (the ZERO LED lights up orange).
• Set the default value specified for the sensor (rough pre-alignment of the zero point) by
actuating the UP button (yellow, at the top) or the DOWN button (yellow, second from the
top).
Default Values:
MPI-WT100, MPI-HL 8113, and MPI HL-8101: 2.0 V
MPI-WT-10: 1.48 V
• Using the SEL button, select the SPAN function. The voltage value at the test
sockets (digital multimeter) should now be 0.4 ± 0.05 V. If this is not the case, select
the ZERO function again, and use the UP or DOWN button to change the default
voltage value until the voltage value at the test sockets after switching to the
SPAN function is within the tolerance range of 0.4 ± 0.05 V. To check the SPAN
value, you must use the SEL button to switch to the SPAN function. When the
adjustments are being made to the ZERO function, the value displayed on the MDO
display unit or, if a PC is connected, the measurement value shown for the input in the
operating software, can be used as a guideline (a displayed value of approximately 0%
of the measuring range Î the SPAN value is within the tolerance).
Note: If the zero point cannot be adjusted (SPAN value not within the tolerance
range), then it is possible that the sensitivity (signal amplification) has been set
too high. In this case, use the SEL button to select the SPAN function and then
press the DOWN button several times (about 20 times) to reduce the sensitivity.
Then repeat the adjustment steps described above.
Person 2:
• Shut off the zero gas supply when person 1 notifies you that the preliminary
adjustment of the zero point has been successfully completed. Then turn on the test
gas (concentration, usually 50% of the measuring range; in no case should this
concentration be less than 20% of the extreme value of the measuring range; see the
operating and maintenance instructions of the sensor).