Stanford Research Systems SR844, User Manual

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Quick Start 1-3
SR844 RF Lock-In Amplifier
Quick Start
This section will lead you through the most basic setup and use of the SR844 RF lock-in amplifier. You
must have selected the line voltage (page i) and connected AC power in order to proceed further.
For this section you will need one BNC cable.
1 Disconnect all cables from the SR844. Check
that the power cord is connected.
2 Turn the power on while holding down the
Setup key.
If the
Setup
key is pressed during power-on, the
instrument performs power-on tests and returns to
its factory preset settings.
3 Wait until the power-on tests are completed. The instrument first displays
SR844
followed by
the unit’s serial number (CH1 and CH2 displays)
and the firmware revision number (Reference
display).
Several tests are performed after this. The message
DATA TEST PASS follows a read/write test to
the processor RAM. BATT TEST PASS refers to
a test of the battery-backed-up memory.
PROG
TEST PASS
follows a test of the instrument
program ROM. DSP TEST PASS refers to the
Digital Signal Processor (DSP). RCAL STD SET
is shorthand for Recall Standard Setup (factory
defaults). Normally, the
Setup button is not pressed
during power-up and the last message will instead
be
RCAL USER SET , which means that the
previous User’s setup has been recalled.
4 If any of the tests FAIL , try power-on once
more with the
Setup
button held down. If the
test FAIL s again, note the ROM version and
Serial Number and contact either the factory
or your local representative.
5 Connect REF OUT on the front panel to the
SIGNAL IN with the BNC cable. The SR844 defaults to the internal oscillator set at
1.00 MHz. The reference mode is indicated by the
INTERNAL
LED. In this mode the SR844
generates a reference signal at the selected
frequency and detects input signals in phase and in
quadrature with this reference. A 1.0 Vpp square
wave reference signal is available at REF OUT.