Enumeration:
7 SI Based Units
1. Length - meter (m)
2. Time - seconds (s)
3. Amount of Substance - mole (mol)
4. Electric Current - ampere (A)
5. Temperature - Kelvin (K)
6. Luminous Intensity - candela (cd)
7. Mass - kilogram (kg)
5 Electronic Instruments
1. Multimeter
2. Ammeter
3. Ohmmeter
4. Oscilloscope
5. Wattmeter
8 advantages
1. Most quantities can be converted by
transducers into electrical or electronic
signals,
2. An electrical or electronic signal can be
amplified, filtered, multiplexed, sampled,
and measured.
3. The measurement can easily be obtained
in or converted into digital form for
automatic analysis and recording.
4. The measured signal can be transmitted
over long distances with the help of cables
or radio links, without any loss of
information.
5. Many measurements can be carried either
simultaneously or in rapid succession.
6. Electronic circuits can detect and amplify
very weak signals and measure the events
of very short duration as well.
7. Electronic measurements provide analog
and digital signals. And because
computers use digital signals, they are
essential for modern science and
technology
8. Higher sensitivity, low power consumption,
and higher degree of reliability are
important features of electronic
instruments and measurements. But for
any measurements, a well defined set of
standards and calibrated units is essential.
5 Functional Elements of an Instrument
1. Primary sensing elements
2. Variable conversion element
3. Manipulation elements
4. Data transmission elements
5. Data presentation elements
2 methods of comparison
1. Direct Comparison Method
● Deflection Method
● Comparison Method
- Null Method
- Differential Method
2. Indirect Comparison Method
10 Static characteristics of an instrument
1. Accuracy
2. Precision
3. Resolution
4. Error
5. Sensitivity
6. Threshold
7. Reproducibility
8. Zero drift
9. Stability
10.Linearity
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