Ametek 7280 Instruction Manual page 123

SENSITIVITY 1
SENSITIVITY 2
When set to voltage input mode, using the Signal Channel menu, the instrument's
full-scale voltage sensitivity may be set to any value between 10 nV and 1 V in a
1-2-5 sequence.
When set to current input mode, using the Signal Channel menu, the instrument's
full-scale current sensitivity may be set to any value between 1 pA and 100 µA (wide
bandwidth mode), 10 fA and 1 µA (normal mode), or 10 fA and 10 nA (low-noise
mode), in a 1-2-5 sequence.
The number reported after the letters DR is the instrument's Dynamic Reserve,
expressed in decibels, as calculated by the following equation:-
DR 20 log
10
Example:-
If AC Gain = 14 dB and SEN = 2 mV then
DR 20 log
10
DR = 46 dB
TIME CONSTANT 1
TIME CONSTANT 2
The time constant of the output filters is set using this control, in the range 1 µs to
100 ks in a 1-2-5 sequence. Settings of 1 ms and below restrict the choice of
instrument outputs to X, Y and Magnitude.
HARMONIC 1 PHASE
HARMONIC 2 PHASE
These controls allows the reference phase of each detection channel to be adjusted
over the range -180° to +180° in 1 m° steps. Adjustment is faster using the Keypad or
Active Cursor controls - see section 4.1.04.
HARMONIC 1 PHASE ±90°
HARMONIC 2 PHASE ±90°
These controls allow the relevant reference phase to be adjusted in steps of ±90°.
X1 OFFSET, Y1 OFFSET, X2 OFFSET and Y2 OFFSET
These are the manual X1/X2 channel and Y1/Y2 channel output offset controls. The
offset levels set by these controls, which can be any value between -300% and
+300% in 0.01% steps, are added to the X1, X2, Y1 or Y2 channel outputs when the
relevant channel offsets are switched on using the Output Channels menu.
Adjustment is faster using the Keypad or Active Cursor controls - see section 4.1.04.
The values are set automatically by the Auto-Offset function. Note that the Auto-
Chapter 5, FRONT PANEL OPERATION
2
ACGain (in dB)
SEN
2
14
0.002
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