Datasheet

50
Example 2: Gain of a Amplifier in a Metering Circuit
The purpose of this example is to work out the Gain of an Amplifier in a Metering Circuit. First
we use Oscilloscope to measure the amplitude of input signal and output signal from the circuit,
then to work out the Gain by using given formulas.
Set the probe menu attenuation coefficient as 10X and that of the switch in the probe as 10X
(see "How to Set the Probe Attenuation Coefficient" on P13).
Connect the oscilloscope CH1 channel with the circuit signal input end and the CH2 channel to
the output end.
Operation Steps:
(1) Push the Autoset button and the oscilloscope will automatically adjust the waveforms of
the two channels into the proper display state.
(2) Push the Measure button to show the right menu.
(3) Select AddCH1 in the right menu.
(4) In the left Type menu, turn the M knob to select PK-PK.
(5) In the right menu, select AddCH1. The peak-to-peak type of CH1 is added.
(6) In the right menu, select AddCH2. The peak-to-peak type of CH2 is added.
(7) Read the peak-to-peak voltages of Channel 1 and Channel 2 from the bottom left of the
screen (see Figure 0-2).
(8) Calculate the amplifier gain with the following formulas.
Gain = Output Signal / Input signal
Gain (db) = 20×log (gain)
Figure 0-2 Waveform of Gain Measurement