TEST AND MEASUREMENT WITH OSCILLOSCOPE

Oscilloscope used to see a form of signal that want to checked. With oscilloscope so we can know about frequency, period, and voltage of the signal. Also with little adjusting we can know the different phase between input signal and output signal.

Oscilloscope consist of 2 main section that is display and control panel. The display like as screen layer on the television but only without color and in function for display the signal input.In this screen contain transvers line in a vertical and horizontal manner that shaping cubicle called div. Horizontal direction represent time axis and vertical line represent voltage axis.

Control panel contain button-button that used for display setting.

Usually oscilloscope consist of 2 channel that can used for check 2 different signal input, for example the first channel for observe input signal and second channel for observe output signal.

Before use oscilloscope to observe the signal so firstly we must setting its in order to avoid fault in Measurement.

Fine point that need to take attention are :

1. Make sure of the modul or circuit that want to checked and oscilloscope already grounded.Besides for safety also to reduce noise from radio frequency interference and AC voltage.

2. Make sure that probe is in good condition.

3. Display calibration can be made by control panel of oscilloscope.

Control knop in panel oscilloscope are :

• Focus : used to arrange focus

• Intensity : For arrange brightness line that displayed on screen.

• Trace : Arrange declivity of line axis Y=0 on screen.

• Volt/div : Arrange what value of voltage that represent with 1(one) div on screen.

• Time/div : Arrange what value of time that represent with 1(one) div on screen.

• Position : For arrange normal position of X axis (when input value is 0 volt)

• AC/DC : Arrange function coupling capasitor at input terminal oscilloscope. If button on AC position so in put terminal connect by capasitor coupling that it will only pass AC component from input signal. However if button switch to DC so signal will measured with its DC component that coming along.

• Ground : used to check location of ground on screen.

• Channel 1 / 2 : choose channel that want to used.

First step using that is calibration

1. For first time must confirm that horizontal line must seen on the screen if no signal input. Where it is necessary to adjusted focus, intensity, X position and Y position. By use of voltage reference that contained in oscilloscope we can be do simple calibration .

2. There are 2 voltage reference that referable that is square voltage 2Vpp and 0.2Vpp with frequency 1 KHz. By connecting probe to terminal voltage reference so it will appear square voltage on the screen.

3. If use 2Vpp voltage reference so at position 1 volt/div (one vertical cell is represent voltage 1 volt) must appeared value peak to peak voltage (Vpp) as many as 2 cell and for time/div 1 ms/div (one horizontal cell is represent time 1 ms) must appeared value 1(one) wave per 1(one) cell. If setting imprecision so need to adjust potensio that contained in the middle position knob replacement of volt/div and time/div.

4. Or at oscilloscope photo above the potensio indicated by “ var”.