Keithley 199 Instruction Manual page 4

SAFETY PRECAUTIONS
The following safety precautions should be observed before operating the Model 199.
This instrument is intended for use by qualified ~personnel who recognize shock hazards and are familiar
with the safety precautions required to avoid possible injury. Read over the manual carefully before operating
this instrument.
Exercise extreme caution when a shock hazard is present at the instrument's input. The American National
Standards Institute (ANSI) states that a shock hazard exists when voltage levels greater than 3OV rms or
42.4V peak are present. A good safety practice is to expect that a hazardous voltage is present in any unknown
circuit before measuring.
Inspect the test leads for possible wear, cracks or breaks before each use. If any defects are found, replace
the test leads.
For optimum safety do not touch the test leads or the instrument while power is applied to the circuit under
test. Turn the power off and discharge all capacitors, before connecting or disconnecting the instrument.
Always disconnect all unused test leads from the instrument.
Do not touch any object which could provide a current path to the common side of the ,+cuit under test
or power line (earth) ground. Always make measurements with dry hands while standmg on a dry, in-
sulated surface, capable of withstanding the voltage being measured.
Exercise extreme safety when~ testing high energy power circuits (AC line or mains, etc). Refer to the High
Energy Circuit Safety Precautions found in paragraph 2.6 (Basic Measurements).
Do not exceed the instrument's maximum allowable input as defined in the~specifications and operation
section.