Keithley 4200-SCS Reference Manual page 6

For maximum safety, do not touch the product, test cables, or any other instruments while power is applied to the circuit under test.
ALWAYS remove power from the entire test system and discharge any capacitors before: connecting or disconnecting cables or jumpers,
installing or removing switching cards, or making internal changes, such as installing or removing jumpers.
Do not touch any object that could provide a current path to the common side of the circuit under test or power line (earth) ground. Always
make measurements with dry hands while standing on a dry, insulated surface capable of withstanding the voltage being measured.
For safety, instruments and accessories must be used in accordance with the operating instructions. If the instruments or accessories are
used in a manner not specified in the operating instructions, the protection provided by the equipment may be impaired.
Do not exceed the maximum signal levels of the instruments and accessories. Maximum signal levels are defined in the specifications and
operating information and shown on the instrument panels, test fixture panels, and switching cards.
When fuses are used in a product, replace with the same type and rating for continued protection against fire hazard.
Chassis connections must only be used as shield connections for measuring circuits, NOT as protective earth (safety ground) connections.
If you are using a test fixture, keep the lid closed while power is applied to the device under test. Safe operation requires the use of a lid
interlock.
If a screw is present, connect it to protective earth (safety ground) using the wire recommended in the user documentation.
!
The symbol on an instrument means caution, risk of danger. The user must refer to the operating instructions located in the user
documentation in all cases where the symbol is marked on the instrument.
The symbol on an instrument means caution, risk of electric shock. Use standard safety precautions to avoid personal contact with
these voltages.
The symbol on an instrument shows that the surface may be hot. Avoid personal contact to prevent burns.
The symbol indicates a connection terminal to the equipment frame.
If this symbol is on a product, it indicates that mercury is present in the display lamp. Please note that the lamp must be properly
disposed of according to federal, state, and local laws.
The WARNING heading in the user documentation explains dangers that might result in personal injury or death. Always read the
associated information very carefully before performing the indicated procedure.
The CAUTION heading in the user documentation explains hazards that could damage the instrument. Such damage may invalidate the
warranty.
Instrumentation and accessories shall not be connected to humans.
Before performing any maintenance, disconnect the line cord and all test cables.
To maintain protection from electric shock and fire, replacement components in mains circuits — including the power transformer, test
leads, and input jacks — must be purchased from Keithley Instruments. Standard fuses with applicable national safety approvals may be
used if the rating and type are the same. The detachable mains power cord provided with the instrument may only be replaced with a
similarly rated power cord. Other components that are not safety-related may be purchased from other suppliers as long as they are
equivalent to the original component (note that selected parts should be purchased only through Keithley Instruments to maintain accuracy
and functionality of the product). If you are unsure about the applicability of a replacement component, call a Keithley Instruments office
for information.
Unless otherwise noted in product-specific literature, Keithley Instruments instruments are designed to operate indoors only, in the
following environment: Altitude at or below 2,000 m (6,562 ft); temperature 0 °C to 50 °C (32 °F to 122 °F); and pollution degree 1 or 2.
To clean an instrument, use a damp cloth or mild, water-based cleaner. Clean the exterior of the instrument only. Do not apply cleaner
directly to the instrument or allow liquids to enter or spill on the instrument. Products that consist of a circuit board with no case or chassis
(e.g., a data acquisition board for installation into a computer) should never require cleaning if handled according to instructions. If the
board becomes contaminated and operation is affected, the board should be returned to the factory for proper cleaning/servicing.
Safety precaution revision as of March 2016.