Measurement of speed:
-One of the basic measurements is that of speed. A wide variety of speed measuring devices are available in the market. They range from a mechanical tachometer to digital and triggered electrical tachometers.
-The best method of measuring speed is to count the number of revolutions in a given time. This gives an accurate measurement of speed. Many engines are fitted with such revolution counters.
-A mechanical tachometer or an electrical tachometer can also be used for measuring the speed.
-The electrical tachometer has a three-phase permanent-magnet alternator to which a voltmeter is attached. -The output of the alternator is a linear function of the speed and is directly indicated on the voltmeter dial.
-Both electrical and mechanical types of tachometers are affected by the temperature variations and are not very accurate. For accurate and continuous measurement of speed a magnetic pick-up placed near a toothed wheel coupled to the engine shaft can be used.
-The magnetic pick-up will produce a pulse for every revolution and a pulse counter will accurately measure the speed.
-One of the basic measurements is that of speed. A wide variety of speed measuring devices are available in the market. They range from a mechanical tachometer to digital and triggered electrical tachometers.
-The best method of measuring speed is to count the number of revolutions in a given time. This gives an accurate measurement of speed. Many engines are fitted with such revolution counters.
-A mechanical tachometer or an electrical tachometer can also be used for measuring the speed.
-The electrical tachometer has a three-phase permanent-magnet alternator to which a voltmeter is attached. -The output of the alternator is a linear function of the speed and is directly indicated on the voltmeter dial.
-Both electrical and mechanical types of tachometers are affected by the temperature variations and are not very accurate. For accurate and continuous measurement of speed a magnetic pick-up placed near a toothed wheel coupled to the engine shaft can be used.
-The magnetic pick-up will produce a pulse for every revolution and a pulse counter will accurately measure the speed.
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