Typical Lock-In Amplifier Experiment - Ametek 7280 Instruction Manual

Chapter 5, FRONT PANEL OPERATION
when in single reference mode is replaced by a key marked Single Reference, as
shown in figure 5-55. To leave dual harmonic mode and return to single reference
mode press the Single Reference key, to switch to dual reference mode, press the
Dual Reference key and to switch to virtual reference mode, press the Virtual
Reference key. The remaining controls operate as already described in section 5.3.13,
except that the Analog Outputs menu operates as described in section 5.5.09
This completes the description of the dual harmonic mode menus.

5.7 Typical Lock-in Amplifier Experiment

The model 7280 is a complex instrument which has many controls and the following
basic checklist may be helpful in setting up the instrument for manual operation in
single reference mode.
Auto-Default
Use the Auto-Default function on the Auto Functions menu to set the instrument to a
defined state.
Selection of Signal Input
Use the Signal Channel menu to select voltage (single-ended or differential) or
current input mode, and connect the signal source to the relevant A and/or B/I input
connector(s) on the front panel.
Selection of Reference Mode
The default setting function will have set the reference mode to internal, which
assumes that the internal oscillator will be used as a source of excitation to your
experiment. Use the Internal Oscillator amplitude and frequency controls to set the
required oscillator output, and connect the output signal from the OSC OUT
connector on the front panel to the experiment.
If using external reference mode, use the Reference Channel menu to select one of
the two external modes, and connect the reference signal to the correct connector.
Auto-Measure
Use the Auto-Measure function on the Auto Functions menu to set the instrument so
that it is correctly displaying the signal.
Other Adjustments
Use the center right-hand key on the Main Display to select the display format
required, and the upper and lower right-hand keys to select the outputs
allocated to the four display positions. The four user-selected Main Display controls
can be chosen using the Select Control key. If the analog outputs of the instrument
are to be used, use the Analog Outputs menu to specify what the output signals at the
CH1 and CH2 connectors on the rear panel should represent.
5-87