Tektronix KEITHLEY SourceMeter 2606B Reference Manual page 91

Section 4: Operation
Safety shield
A safety shield must be used whenever hazardous voltages (>30 V
present in the test circuit. To prevent electrical shock that could cause injury or death, never
use the 2606B in a test circuit that may contain hazardous voltages without a properly
installed and configured safety shield.
The safety shield can be metallic or nonconductive and must completely surround the device under
test (DUT) test circuit. A metal safety shield must be connected to a known protective earth (safety
ground). See
nonconductive enclosure.
Safety shielding and hazardous voltages
The maximum output voltage for a 2606B channel is 20 V, which is considered a nonhazardous level.
However, using multiple voltage sources in a series configuration or
can cause test circuit voltage to exceed 42 V. For example, if a 2606B has LO driven to 100 V by a
Model 2612B, the test circuit voltage could exceed 42 V. See
for information on using multiple System SourceMeter
Use #18 AWG wire or larger for connections to safety earth ground and chassis.
Guarding
A driven guard is always enabled and provides a buffered voltage that is at the same level as the
input/output HI voltage. The purpose of guarding is to eliminate the effects of leakage current (and
capacitance) that can exist between HI and LO. Without guarding, leakage and capacitance in the
external high-impedance test circuit could be high enough to adversely affect the performance of
the 2606B.
Guarding is recommended when test circuit impedance is >1 GΩ.
See Guard (on page 8-12) for details on the principles of guarding.
The guard shield can be the shield of a coaxial cable or an insulated foil that surrounds
the conductor.
4-8
Test fixtures (on page 4-11) for important safety information on the use of a metal or a
Model 2606B System SourceMeter® Instrument Reference Manual
TSP advanced features
®
instruments.
2606B-901-01 Rev. C November 2021
, 42 V ) will be
RMS PEAK
floating a SMU (on page 4-12)
(on page 14-57)