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CHAPTER 2:
System Overview
Model CRX-6.5K Probe Station
2.4.8.4 Measurement Voltage Limits
The Model CRX-6.5K probe station is specified for signal voltages below 60 VDC and
30 V
rms
, referred to as non-hazardous live voltage. The sensor, heater and power
supply voltages entering the probe station are all below this voltage. More
importantly, testing criteria established for the CE mark assumes there will be no
hazardous live voltage operating in the probe station.
Many of the guarded sources, electrometers and other pieces of electronic test
equipment used in DC or RF measurements are capable of operating from hundreds
of volts to over thousands of volts. The Model CRX-6.5K probe station is not
specifically designed to ensure operator safety when these voltages are present.
Because Lake Shore has no way to predict how the hazardous live voltages would be
configured or operated, it is impossible for us to guarantee safety in the event of
improper operation, accidental misconnection or component failure. The Model CRX-6.5K
does not include the safety interlocks, current limits or earth safety ground system that
are necessary for safely working with hazardous live voltages.
FIGURE 2-28
Guarding with back side voltage bias using a triaxial sample holder
Triaxial signal connector
Cryogenic
coaxial cable
Radiation shield stage
ZN50
Probe
Sample stage
Cryogenic
coaxial cable
Probe
arm
base
Probe arm shield
To temperature
controller chassis
19-pin
connector
Thermal
anchors
Shield
Vacuum chamber base
Triaxial
sample holder
Bias voltage
Triaxial feedthrough
Guard
INSULATOR
CONDUCTOR
CONDUCTOR
INSULATOR
CONDUCTOR