Main Controls: Oscillator - Ametek 7230 Instruction Manual

Chapter 5, WEB CONTROL PANEL OPERATION

5.3.05 Main Controls: Oscillator

5-20
Time/Step
This control defines the time per point within the automatic search.
Search
Clicking the Search button starts the internal oscillator at the defined start
frequency and increases it at the selected step size and rate. If the instrument
detects a signal greater than 50% of full-scale then the search stops.
Frequency
This indicator shows the current frequency at which the Reference 1 channel is
operating.
Harmonic
This control allows selection of the harmonic of the reference frequency at which the
reference 1 channel of the lock-in amplifier operates. It can be set to any value
between 1F and 127F, but most commonly is set to 1F.
Phase
This control allows the reference phase for the first set of demodulators to be
adjusted over the range -180° to +180° in 1 m° steps.
+90 Deg
Each click of this button adds 90° to the reference 1 phase setting.
Auto Phase
Clicking this button initiates an Auto-Phase operation, where the value of the signal
phase with respect to the reference is computed and an appropriate phase-shift is
then introduced into the reference 1 channel so as to bring the difference between
them to zero. The intended result is to null the output of the Y channel while
maximizing the output of the X channel.
The Oscillator controls, shown in figure 5-23, affect the internal oscillator.
Amplitude
This control sets the amplitude of the signal at the front panel OSC OUT connector
to any value between 1 mV and 5 V rms.
Frequency
The frequency of the instrument's internal oscillator may be set, using this control, to
any value between 0.001 Hz and 120.000 kHz (or 250.000 kHz if the instrument is
fitted with the 7230/99 option) with a 1 mHz resolution.
Figure 5-23, Oscillator Controls