Fluke PM3370B user manual Input Attenuator Manual + Automatic, Function of key pair AMPL/VAR

FUNCTION REFERENCE 5 - 39

INPUT ATTENUATOR MANUAL + AUTOMATIC

Description:

The oscilloscope’s input has a wide range of sensitivities. This enables signals of different amplitudes to be displayed on the available screen area. Sensitivity adjustment is done with key pair AMPL/VAR or a single AMPL toggle key (for the External Trigger input).

Input sensitivity increases when the top key (mV) is pressed; it decreases when the lower key (V) is pressed. The sensitivity adjustment can be done in steps or continuously; switching between these modes is done by pressing both keys simultaneously. The CRT readout resolution correspondingly changes. The amplitude of a signal can be determined as described under the ’SCREEN CONTROLS AND GRATICULE’ function. The AUTO RANGE key activates a continuous automatic adjustment of input sensitivity. The result is a signal amplitude on the screen between 2 and 6.4 divisions. This functions in digital mode for input sensitivities up to 50 mV/div. For more information, refer to the AUTO RANGE function.

For the External Trigger input, the input sensitivity can be adjusted to the two most commonly used settings (1 V/div and 100 mV/div). Selection is done with a single toggle key AMPL.

CH1 100mV

AMPL/div

AUTO

RANGE

AMPL

CH1 500mV

MAT4165

AMPL/div9312

Function of key pair AMPL/VAR

Key sequence:

AMPL

Key pair to adjust the vertical input sensitivity in coarse or fine steps.

ST6182