Metrohm 785 DMP Titrino - Manual (Page 142)

4.2. Diagnosis
785 DMP Titrino
139
4.2.3 Equipment required: Equipment required: Equipment required: Equipment required:
− voltage calibrator, e.g. 1.642.0010 Metrohm pH Simulator
or 1.767.0010 Calibrated Reference for mV, pH, ê æS, °C
− highly insulated interconnection cable 6.2108.060
− resistor switch-box, class 0.1 % (or resistor 14.3 k, 0.1 %)
− cable 3.496.5070
− exchange units, if possible with different cylinder volumes (or 3.496.0070 dummy exchange unit)
− stop watch or watch with second hand
− digital or analogue voltmeter (if need be, connect a calibrated recorder)
− 2 connecting cables with 4 mm banana plugs
− test plug 3.496.8550 (necessary only if plug ‘Remote’ should be checked)
− test plug 3.496.8560 (necessary only if plug ‘RS 232’ should be checked)
1 Prepare instruments for diagnostic test
• Power off.
• Disconnect all external connections (cables at rear, except mains cable and keyboard).
• Remove exchange unit.
• Power on and immediately press and hold the <9> key until the powerup test pattern
disappears.
diagnose press key 0...9
2 Perform display test
• Press <2>.
display test
• Press .
Characters for a visual check of the display are generated on the eight lines.
Test sequence:
a) The display is cleared and overwritten from the top left to the bottom right with a dot
pattern ( ²²²²²²²² ).
b) The display is cleared and overwritten from the top left to the bottom right with a dot
pattern( °°°°°°°°.
c) The display is continuously cleared and overwritten from the top left to the bottom
right with the complete character set. At the same time with moving display the
LED’s „COND.“, „STATISTICS“ and „SILO“ are swtiches on and off.
• The test sequence can be held and then continued at any time by pressing <5>.
• Block 2 is quit by pressing .
diagnose press key 0...9