Fully Automatic Digital Instrument: Fully Automatic Digital Instrument – A multimeter with automatic polarity indication, automatic zero correction and automatic ranging (of course coupled with automatic decimal point indication) only needs a signal applied to its input, and a command as to what quantity (Vdc, Vac, I or R) to measure; it does all the …
Working Principle of Digital pH Meter | Block Diagram: Working Principle of Digital pH Meter – The Digital Measurement of hydrogen ion activity (pH) in a solution can be accomplished with the help of a pH meter. For those unfamiliar with the terminology, a very brief review is included. pH is a quantative measure of …
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Digital Tachometer Working Principle: Digital Tachometer Working Principle technique employed in measuring the speed of a rotating shaft is similar to the technique used in a conventional frequency counter, except that the selection of the gate period is in accordance with the rpm calibration. Let us assume, that the rpm of a rotating shaft is …
IEEE 488 Bus Block Diagram: The purpose of IEEE 488 BUS is to provide digital interfacing between programmable instruments. There are many instrumentation systems in which interactive instruments, under the command of a central controller, provide superior error-free results when compared with conventional manually operated systems. Problems such as impedance mismatch, obtaining cables with proper …
Microprocessor Based Instruments: Microprocessor Based Instruments – Digital instruments are designed around digital logic circuits without memory. The use of microprocessors as an integral part of measuring instruments has given rise to a whole new class of instruments, called intelligent instruments. Figure 6.28 shows a block diagram of a microprocessor based impedance measuring instrument. The …
Digital Capacitance Meter Block Diagram: Digital Capacitance Meter – Since the capacitance is linearly proportional to the time constant, when a capacitor is charged by a constant current source and discharged through a fixed resistance, we can use a 555 timer along with some digital test equipment to measure capacitances. One obvious way is to …
Digital Phase Meter Block Diagram and Working Principle: Digital Phase Meter – The simplest technique to measure the phase difference between two signals employs two flip-flops. The signals to be fed must be of the same frequency. First, the signals must be shaped to a square waveform without any change in their phase positions, by …
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Automation in Digital Instruments: Automation in Digital Instruments – One of the advantages of digital multimeters is their ease of operation. The reading is easy to take and does not lend itself to errors of interpretation. Moreover, the number of ranges is limited because the ranges move in steps of 10 (instead of the √10 …
Digital Measurement of Frequency (Mains): Digital Measurement of Frequency (Mains) – The conventional method of measuring the frequency of an electrical signal consists of counting the number of cycles of the input electrical signal during a specified gate interval. The length of the gate interval decides the resolution of the Measurement. The shorter the gate …
Different Modes of Operation of Electronic Counter: The decade counter can be easily incorporated in a commercial test instrument called an electronic counter. A decade counter, by itself, behaves as a totaliser by totalling the pulses applied to it during the time interval that a gate pulse is present. Typical Different Modes of Operation of …
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