Safety
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 specifi ed in t
he 
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 defi ned in the specifi cations and operating information and shown on the instrument 
panels, test fi xture panels, and switching cards. 
When fuses are used in a product, replace with the same type and rating for continued 
protection against fi re hazard. 
Chassis c
onnections must only be used as shield connections for measuring circuits, NOT as 
protective earth (safety ground) connections. 
If you are using a test fi xture, 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 warning, risk of electric 
shock. Use standard safety 
precautions to avoid personal contact with these voltages.
The       symbol indicates a connection terminal to the equipment frame.
The         symbol on an instrument means caution, risk of hazard. 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 shows that the surface may be hot. Avoid personal contact to 
prevent burns.
I
f 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 hazards 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 expla
ins hazards that could damage the 
instrument. Such damage may invalidate the warranty.
The CAUTION heading with the        symbol in the user documentation explains hazards that 
could result in moderate or minor injury or damage the instrument. Always read the associated 
information very carefully before performing the indicated procedure. Damage to the instrument 
may invalidate the warranty.
Instrumentation and accessories shall not be connected to huma
ns. 
Before performing any maintenance, disconnect the line cord and all test cables. 
To maintain protection from electric shock and fi re, replacement components in mains circuits 
— including the power transformer, test leads, and input jacks — must be purchased from 
Keithley. 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 wi
th 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 to maintain accuracy 
and functionality of the product). If you are unsure about the applicability of a replacement 
component, call a Keithley offi ce for information. 
Unless otherwise noted in product-specifi c literat
ure, Keithley 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 cloth dampened with deionized wat
er 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 instr
ument. 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 aff ected, the board should be returned to the factory for proper cleaning/servicing. 
Safety precaution revision as of June 2017.