
86
Unit Operation Checks
7. IS CTRL-A ASSY
Outline
IS CTRL-A provides functions for filament control and ion-source temperature control. It
also functions as a relay board to introduce the lens voltages sent from MAIN CTRL-A into
the vacuum vessel.
Filament control (EI mode)
If one filament is selected, the other filament can be used as a trap electrode. The filament
potential (emission voltage) and the amount of thermoelectrons emitted from the filament
(emission current) are set using D/A. When the filament is turned on, current flows into the
filament, causing the emission of thermoelectrons. A proportion of these reach the trap
electrode that is held at a potential of +10V, and are measured as the trap current. An error
amplifier operates to control the filament current to maintain the trap current equal to the set
emission current value.
Ion-source temperature control adjustment
The voltage applied to the heater is proportional to the duty ratio of the PWM waveform
generated by the CPU. A platinum (Pt) sensor measures the temperature.
Operation Check Method
If an abnormality occurs, follow the procedures below to check the operation of the IS
CTRL-A PCB to efficiently diagnose the problem.
Signal peak abnormality: Checks 1, 2, 3, 4, 5
Ion-source temperature abnormality: Checks 1, 6, 7
Caution
A voltage of -200VDC is supplied to the PCB. To avoid electric shocks or damage to
the assembly, touch only the points instructed.
1. Checking the supply voltages
CP3 +15V (normal range: +14.25 to +15.75VDC)
CP5 -15V (normal range: -14.25 to -15.75VDC)
CP9 +24V (normal range: +22.7 to +25.3VDC)
When CP6 is measured with respect CP7: +5V (normal range: +4.9 to +5.3V when filament
is off)
2. Checking the lens voltages
Содержание GCMS-QP2010 Series
Страница 1: ...1 225 00612A Gas Chromatograph Mass Spectrometer GCMS QP2010 Service Manual...
Страница 14: ...14 Do not increase the ion source or interface temperature above the level required for analysis...
Страница 27: ...27...
Страница 71: ...71 Wiring Diagrams 1 Wiring diagram Overall Wiring Diagrams...
Страница 72: ...72 Wiring Diagrams 2 Wiring diagram MAIN POWER ASSY...
Страница 73: ...73 Unit Operation Checks 3 Wiring diagram Details...
Страница 76: ...76 MAIN POWER ASSY Block Diagram Parts inside the broken box are in the MAIN POWER ASSY...
Страница 79: ...79 DC POWER A Block Diagram...
Страница 84: ...84 MAIN CTRL A Block Diagram...
Страница 85: ...85...
Страница 90: ...90 IS CTRL A Block Diagram...
Страница 94: ...94 HV PCB ASSY block diagram 1 UNNCI case of model EI CI 2 NCI case of model NCI...
Страница 98: ...98 IG CTRL A PCB Block Diagram...
Страница 103: ...103 CP6 24V normal range 22 7 to 25 3VDC CP7 24V normal range 22 7 to 25 3VDC CP12 5V normal range 4 8 to 5 3VDC...
Страница 109: ...109 DI CTRL A block diagram...
Страница 145: ...121 5 Remove the IS CTRL A Board Unit Disconnect the two connectors Remove the three screws and the spacer screw...
Страница 150: ...126 Do not remove the 2 screws on the right side Remove the 2 screws on the left side...
Страница 151: ...127 Remove cardboard Move the TW300 left by holding in both hands...
Страница 154: ...130 10 Preparation of new TW300 New TW 300 Removed TW300 Check the name plate Old type New type...
Страница 155: ...131 Remove the cap of outlet Loosen the 3 fixing screws and remove the plate Remove the o ring...
Страница 158: ...134 Hook the right side hooks on the neck of inlet Attach the left side screws and hooks Fasten lightly the 4 screws...
Страница 160: ...136 Remove the cardboard Completion of TMP mounting...
Страница 161: ...137 12 Fix the flange to outlet Place the flange on the outlet Do not forget to place o ring...
Страница 163: ...139 Slide fast the IS CTRL A board down and fix it 4 screws Connect the two connectors...
Страница 164: ...140 14 Place the covers Place the front cover Place the front door...