Elenco 30MHz Dual Trace - Manual (Page 40)

Operating Instru ctions
OSCILLOSCOPE INSTRUCTION MANUAL
37
1. When he oscilloscope is used to make measurements in equipment that contains
high voltage, there is always a certain amount of danger from electrical shock.
The person using the oscilloscope in such conditions should be a qualified
electronics technician or otherwise trained and qualified to work in such
circumstances. Observe the TEST INSTRUMENT SAFETY recommendations
listed on the inside front cover of this manual.
2. Do not operate this oscilloscope with the case removed unless you are a qualified
service technician. High voltage up to 1250 voltages is present when the unit is
operating with the case removed.
3. The ground wire of the 3-wire ac power plug places the chassis and housing of the
oscilloscope at earth ground. Use only a 3-wire outlet, and do not attempt to
defeat the ground wire connection or float the oscilloscope; to do so many pose a
great safety hazard.
4. Special precautions are required to measure or observe line voltage waveforms
with any oscilloscope. Use the following procedure:
a. Do not connect the ground clip of the probe to either side of the line. The clip is
already at earth ground and touching it to the hot side of the line may “weld” or
disintegrate” the probe tip and cause possible injury, plus possible damage to
the scope or probe.
b. Insert the probe tip into one side of the line voltage receptacle, then the other.
One side of the receptacle should be “hot” and produce the waveform. The other
side of the receptacle is the ac return and no waveform should result.
EQUIPMENT PROTECTION PRECAUTIONS
The following precautions will help avoid damage to the oscilloscope:
1.Never allow a small spot of high brilliance to remain stationary on the screen for
more than a few seconds. The screen may become permanently burned. A spot
will occur when the scope is set up for X-Y operation and no signal is applied.
Either reduce the intensity so the spot is barely visible, apply signal, or switch
back to normal sweep operation. It is also advisable to use low intensity with
AUTO triggering and no signal applied for long periods. A high intensity trace at
the same position could cause a line to become permanently burned onto the
screen.
WARNIN G!
The following precautions must be observed to help prevent electric
shock:
SAFETY PRECAUTIONS