The measurement of time intervals

 

During the measuring of time intervals it is necessary to put the handle SMOOTHLY in the sector g into the far right position. In this position handle SMOOTHLY scan is calibrated and is corresponds to graduation of switch LENGTH TIME / UNDER.

Measurement area of pulse is desirable to establish in the center of the screen using handles "«".

Toggle of duration and the multiplier toggle of scan is necessary to put in a such position, in order to measuring interval of time occupied on the screen no less than four scale point. To reduce measurement error by the thickness of the line scan measurements are calculated from the right or left edges of the image lines. Accuracy of measurement of time intervals increases with the length of measuring distance on the CRT screen. Therefore, during the measurements it should be working correctly chosen the duration of refresh.

Measuring time interval is determined by the product of three variables: length of measuring time interval on the screen horizontally to scale point, value of time per unit scale point in this position of switch DURATION TIME / UNDER. and scan multiplier value ("x1" or "x0, 2").

 

 

Measuring of frequency

 

The frequency of signal can be determined by measuring of its period T:

Calculate the distance in division of integer signal periods, to be concluded around 10 divisions of the scale.

Let's take, 5 periods cover a distance of 8.45 divisions at duration of scan Tp= 2 ms / ed.

Then the signal frequency:

kHz

 

Measuring the amplitude of investigated signals

 

Measuring the amplitude of investigated signals being investigated is made in this way. On the input of amplifier in In-I or-II sent a signal. Handle AMPLIFICATION should be in the right position. With handles " "and "«" signal is shifted with the required scale point, and image is vertically measured in division.

The amplitude value of the investigated signal in volts will equal the product of the measured size of the image in divisions and digital marks of switch V/ UNDER. Working with remote divisor 1:10 received result should be multiplied by 10. Accuracy of amplitudes measurement is guaranteed at image size from 3 to 7 divisions. Therefore, the input attenuator is necessary to put in such a position when the size of the investigated signal oscillogram is the largest in the limits of working screen part.

 

Order of work

 

1. Draw the front panels of pulse generator 54 and H5- oscilloscope C1-55.

2. Explore the purpose of buttons and switches. Sign them.

3. Using scales and switches on the front panel of the generator, set:

3.1. pulse frequency 80 kHz by pressing the black button " " FREQUENCY REPETITION and by turning of scale device, align the figure 8 on a black scale with red slash on fixed radius;

3.2. 1 ms - pulse delay by pressing the white button of switch TIME SHIFT and rotating device of scale, to combine a number 1 on the white scale with a red slash on fixed radius;

3.3. 2 ms - pulse duration by pressing the white button "x1" of switch DURATION and by turning of scale device, align the number 2 on the white scale with a red slash on fixed radius;

3.4. pulse amplitude 0.5 - 1, by pressing one of the 4 top buttons of voltage divider (x1, x0, 3; x0 1, x0, 03) and turn the potentiometer AMPL, then to set the amplitude of 1 V with help of voltmeter scale;

3.5. given impulses polarity by pressing one of two buttons in the top right corner of the front panel of the generator.

4. Press the top button RUN, switch on generator by NETWORK tumbler and warm device for 5 min.

5. Prepare to work oscillograph C1-55:

5.1. using the switch on the front panel of oscilloscope OPEN INPUT "=" and CLOSED INPUT" " set mode of open input on both iputs of vertical deviation amplifiers;

5.2. synchronize oscilloscope by proactive synchropulses of generator.

To do this:

- Switch SYNCHRONIZING of oscilloscope put to the position EXTERNAL ;

- Connect with the cable output jack synchropulses of generator with jack INPUT synchronization of oscilloscope;

- set by the tumbler SYNCHROIMPULSES OF GENERATOR necessary polarity of synchropulses and by handle AMPL – necessary synchropulse amplitude.

6. Connect the generator output to one inputs of oscilloscope.

7. Switch on an oscilloscope. With handles STAB and LEVEL by choosing the optimal duration of scanning to achieve a stable display of two pulses on the screen.

8. Measure the period of pulse pass and determine their frequency (see sect. 3.4).

9. Draw oscillograms of pulses and measure with oscilloscope pulse parameters of oscilloscope:

- time delay ;

- duration of forward front ;

- pulse duration ;

- pulse amplitude .

By measuring the period, duration of pulses and forward front it is necessary to establish the optimal duration of scanner.

10. Taking the indications of pulse generator H5-54 for true, to determine the absolute and relative error of measurements τ, tзат, tф, τі, Um.

11. Make the conclusions about work.

12. Make a report.

 

Content of report

 

The report must contain:

5.1. The purpose of the laboratory work.

5.2. The basic technical characteristics and parameters of pulse generator and H5-54 and TWO-BEAM oscilloscope S1-55.

5.3.Results of video pulse parameters research.

5.4. Conclusions due to results of research.