Ametek 7280 Instruction Manual page 109

Main Menu 1 accesses the Dual Reference Channel menu, shown in figure 5-39.
Figure 5-40, Dual Reference Channel Menu
The Dual Reference Channel menu has five controls affecting the instrument's
reference channel. Changes to the setting of these controls can be made by using the
adjacent keys.
REF SOURCE1
This control allows selection of the source of reference signal used to drive the
reference 1 circuitry, and has two settings:-
REAR
In this setting the reference1 channel is configured to accept a suitable external
reference source applied to the rear panel REF TLL input connector
FRONT
In this setting the reference1 channel is configured to accept a suitable external
reference source applied to the front panel REF IN input connector
REF1 HARMONIC
This control sets the harmonic of the applied external reference frequency at which
the lock-in amplifier's reference 1 channel operates, in the range 1 st (fundamental
mode) to 32 nd.
REF2 HARMONIC
This control sets the harmonic of the internal reference frequency at which the lock-
in amplifier's reference 2 channel operates, in the range 1 st (fundamental mode) to
32 nd.
REF1 PHASE
REF2 PHASE
These two controls allow the reference phase of reference
independently adjusted over the range -180° to +180° in 10m° steps. Adjustment is
faster using the Keypad or Active Cursor controls - see section 4.1.04.
Chapter 5, FRONT PANEL OPERATION
and reference
1
to be
2
5-63