Experiments with oscilloscope

Experiments with oscilloscope

INTRODUCTION
The purpose of this tutorial is to observe oscilloscope, function (signal) generator and how to use its functions for testing purposes. We used oscilloscope to observe voltage signals as a function of time. In this practical we used AL210/20MHz (YOKOGAWA) oscilloscope, GFC-8217A INSTEK signal generator, digital multimeter, AC Voltage supply, 4.7k resistor, 0.047μF capacitor and related accessories.

An oscilloscope is a voltage measurement device. Unlike a voltmeter, an oscilloscope does not display a single number.it is display signals – voltages that are function of time. Oscilloscopes can measure signal parameters like frequency, peak-to-peak voltages, RMS values of signals, etc. oscilloscope displays time-varying signal (see Figure 1: AL210 oscilloscope) and we need a voltage source that produces a time-varying signal. A signal generator produces different kinds of signals for testing purposes. Those signals include sinusoidal signals, triangles and square wave signals.
Before using oscilloscope for the practical we must calibrate the oscilloscope. Calibration is the comparison of a measurement against an equal or better standard. A standard measurement can find in OCR, it can be considered as a reference.
We used oscilloscope and function generator for AC & DC voltage measurements with their uncertainties. Uncertainty is half of minimum reading.it is called as propagation error. Example: 4.2 ±0.1V X 0.5V
According to the oscilloscope measurement, in above example 4.2 is our reading value. ±0.1V is propagation error or uncertainty.0.5V is voltage scale.
For find out actual values of a resistors and capacitors we used Digital multimeter. With the help of Oscilloscope, function generator, resistor and capacitor we determined time constant of an R-C Circuit. Using same components and sin wave form of the signal generator we measured the phase shift of the output voltage compared to the input in R-C Low-Pass Filter and R-C High-Pass Filter.

Next Part will continue with another tutorial. :)
Lecturer/Admin : LaaHiru Fernando.