Safety And Preparation For Use - Stanford Research Systems SR844 User Manual

Safety and Preparation For Use

WARNING!
Dangerous voltages, capable of causing injury or death, are present in this
instrument. Use extreme caution whenever the instrument cover is
removed. Do not remove the cover while the unit is plugged into a live
outlet.
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 The SR844 operates from a 100V, 120V, 220V, or 240V nominal AC power source
Selection 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
pull 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 that the desired
voltage is visible when the circuit board is pushed firmly into its slot. Push the fuse-pull
lever back into 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 SR844 has a detachable, three-wire power cord for connection to the power source
and to 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.
Service
Do not attempt to service or adjust this instrument unless another person, capable of
providing first aid or resuscitation, is present.
Do not install substitute parts or perform any unauthorized modifications to this
instrument. Contact the factory for instructions on how to return the instrument for
authorized service and adjustment.
Fan The fans in the SR844 are required to maintain proper operation. Do not block the vents
in the chassis or the unit may not operate properly.
Warning! Regarding Use With Photomultipliers and Other Detectors
The front end amplifier of this instrument is easily damaged if a photomultiplier is used
improperly with the amplifier. When left completely unterminated, a cable connected to a
PMT can charge to several hundred volts in a relatively short time. If this cable is
connected to the inputs of the SR844 the stored charge may damage the front-end op
ampls. To avoid this problem, always connect the PMT output to the SR844 input before
turning the PMT on.
SR844 RF Lock-In Amplifier
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