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Agilent Technologies Helium Leak Detector
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Figure A-3 shows the input circuit sketch. All inputs are optically isolated 3300 Ohm
resistive loads in series with the LEDs of the opto-isolators and voltage level from +5 VDC to
+24 VDC. The required pulse inputs are 200 ms minimum pulse width.
Figure A-3 Optically Isolated Input Circuit Sketch