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Custom Modifications
The 9412/9412A is microprocessor-controlled and employs a flexible and expandable user-
interface. New features and operating modes often can be added, without hardware modifi-
cations, by merely modifying the software contained inside the 9412/9412A. Most modifica-
tions can be made for a very modest charge -- contact Quantum Composers for details.
Safety Issues
Normal use of test equipment exposes you to a certain amount of danger from electrical
shock because testing must be performed where exposed voltage is present. An electrical
shock causing 10 milliamps of current to pass through the heart will stop most human heart-
beats. Voltage as low as 35 VDC or RMS AC should be considered dangerous and hazardous
since it can produce a lethal current under certain conditions. Higher voltages pose an even
greater threat because such voltage can more easily produce a lethal current. Your normal
work habits should include all accepted practices that will prevent contact with exposed high
voltage, and that will steer current away from your heart in case of accidental contact with a
high voltage. You will significantly reduce the risk factor if you know and observe the follow-
ing safety precautions:
1. Do not expose high voltage needlessly. Remove housings and covers only when necessary.
Turn off equipment while making test connections in high-voltage circuits. Discharge high-voltage
capacitors after removing power.
2. If possible, familiarize yourself with the equipment being tested and the location of its high volt-
age points. However, remember that high voltage may appear at unexpected points in defective
equipment.
3. Use an insulated floor material or a large, insulated floor mat to stand on, and an insulated work
surface on which to place equipment. Make certain such surfaces are not damp or wet.
4. Use the time-proven "one hand in the pocket" technique while handling an instrument probe.
Be particularly careful to avoid contacting a nearby metal object that could provide a good ground
return path.
5. When testing AC powered equipment, remember that AC line voltage is usually present on
some power input circuits, such as the on-off switch, fuses, power transformer etc., any time the
equipment is connected to an AC outlet, even if the equipment is turned off.
