precautions while using cathode ray oscilloscope

Precautions while using Cathode Ray Oscilloscope

The cathode-ray oscilloscope (CRO) is a common laboratory instrument that provides accurate time.
31. Aim
To study the different waveforms, to measure peak and rms voltages and the frequency of A.C.
32. measurement of frequency
An unknown frequency source signal generator is connected to y plates of C.R.O . Time base signal is connected to x plates internally connected . We get a sinusoidal wave on the screen, after the adjustment of voltage sensitivity band switch Y plates and time base band switch X plates . The horizontal length l between two successive peaks is noted. When this horizontal length l is multiplied by the time base m i.e. sec div , we get the time period T .The reciprocal of the time period 1 T gives the frequency f . This can be verified with the frequency, measured by the multi meter.
33. Digital storage oscilloscope
The digital storage oscilloscope, or DSO for short, is now the preferred type for most industrial applications. Instead of storage type cathode ray tubes, DSOs use digital memory, which can store data as long as required without degradation. A digital storage oscilloscope also allows complex processing of the signal by high speed digital signal processing circuits.
34. Dual beam oscilloscope
A dual beam oscilloscope was a type of oscilloscope once used to compare one signal with another. There were two beams produced in a special type of CRT.
35. Analog sampling oscilloscope
The principle of sampling was developed during the 1930s in Bell Laboratories by Nyquist, after whom the sampling theorem is named. The first sampling oscilloscope was, however, developed in the late 1950s at the Atomic Energy Research Establishment at Harwell in England by G.B.B. Chaplin, A.R. Owens and A.J. Cole.
36. Time base
With that controller one can vary the unit for the time scale, i.e.Time Div.box length on screen is 1 cm. This will be technically realized in that oscilloscope in fitting the frequency of the saw tooth generator. This function allows to zoom in x direction.
37. Delayed sweep
Another feature of most good scopes is Delayed Sweep. Delayed Sweep, allows the user that could be you, if you behave and eat your vegetables to trigger on an event and observe the signal after some predetermined time interval. For example: if you wanted to observe one single scan lineout of 525in a television signal, you would trigger off of the beginning of each television field time 16.67 msec but holdoff displaying that particular scan line HD 63.5 usec until the correct amount of time has passed. In essence the Delayed Sweep is just a fancy One Shot multivibrator with a ten turn pot, triggered from the scope s normal sweep circuit; and holds off the sweep across the screen until some time intervaldetermined by our old friends Ms.
38. Cathode ray tube experiment
Now they applied magnetic field across the cathode ray tube by using external magnetic field. The negatively charged cathode ray or electrons are deflected.
39. Lichtenberg figures
Specimens were previously charged by injecting a cumulative charge of 2.7 microCoulombs cm2 using an electron beam with a nominal beam energy of 4.0 MeV.
40. Heat light and sound
The diagrams below show waves displayed by a CRO cathode ray oscilloscope . Which wave is least likely to have been made by a musical instrument.