Safety And Preparation For Use - Stanford Research Systems SR570 User Manual

WARNING: Dangerous voltages, capable of causing death, are present in this instrument. Use
extreme caution whenever the instrument covers are removed.
************ CAUTION ************
This instrument may be damaged if operated
with the LINE VOLTAGE SELECTOR set for
the wrong ac line voltage or if the wrong fuse is
installed.
LINE VOLTAGE SELECTION
When the AC power cord is connected to the unit
and plugged into an AC outlet, the unit
automatically switches the amplifier power source
from internal battery operation to line operation.
The internal batteries are charged as long as AC
power is connected.
The SR570 operates from a 100V, 120V, 220V, or
240V nominal AC power source having a line
frequency of 50 or 60 Hz. Before connecting the
power cord to a power source, verify that the
LINE VOLTAGE SELECTOR card, located in the
rear panel fuse holder, is set so that the correct AC
input voltage value is visible.
Conversion to other AC input voltages requires a
change in the fuse holder voltage card position and
fuse value. Disconnect the power cord, open the
fuse holder cover door and rotate the fuse-pull
lever to remove the fuse. Remove the small
printed circuit board and select the operating
voltage by orienting the printed circuit board so
the desired voltage is visible. Push the card firmly
into its slot. Rotate the fuse-pull lever back to its
normal position and insert the correct fuse into the
fuse holder.
LINE FUSE
Verify that the correct line fuse is installed before
connecting the line cord. For 100V/120V, use a
1 Amp fuse and for 220V/240V, use a 1/2 Amp
fuse.
LINE CORD
The SR570 has a detachable, three-wire power
cord for connection to an AC power source and to

Safety and Preparation for Use

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SR570 Low-Noise Current Preamplifier
a protective ground. The exposed metal parts of
the instrument are connected to the outlet ground
to protect against electrical shock. Always use an
outlet which has a properly connected protective
ground.
CONNECTION TO OTHER INSTRUMENTS
All front panel BNC shields are isolated from the
chassis ground and the power outlet ground via a
1MΩ resistor. Do not apply any voltage to either
the shields or to the outputs. The outputs are not
protected against connection to any potential other
than circuit ground.
VENTILATION
Always ensure adequate ventilation when
operating the SR570. The unit will generate heat
while charging batteries.
POWER-UP
All instrument settings are stored in nonvolatile
memory (battery backed-up RAM) and are
retained when the power is turned off. They are
not affected by the removal of the line cord. If the
power-on self test passes, the unit will return the
settings that were in effect when the power was
last turned off. If an error is detected or if the
backup battery is exhausted, the default settings
will be used. Additionally, if the FILTER RESET
key is held down when the power is turned on, the
instrument settings will be set to the defaults
shown below:
Sensitivity = 1 µA/V, calibrated
Invert = off
Input Offset = +1 pA, calibrated, off
Bias = 0 V, off
Filters = none
Hi Pass Freq = 0.03 Hz
Lo Pass Freq = 1 MHz
Gain Mode = Low Noise