Measuring instruments. Analog measuring instruments: An instrument with a moving coil. Extending the measuring instrument range by the moving coil. An instrument with a movable iron. Electrodynamic instrument. Extending the voltmeter and ampere meter measuring range. Oscilloscopes: Time base, Trigger time base, XY mode. Multi-channel oscilloscopes. Digital oscilloscopes. Measuring bridges: DC measuring bridges. Wheatstone bridge, Kelvin bridge. AC measuring bridge. Unbalanced measuring bridges. Measuring bridges with multiple sources. Measuring compensators: DC measuring compensators. Alternating measuring compensators. Measurement of electrical quantities. Measuring the resistance/impedance, Inductance measurement/mutual inductance, Measuring capacitance, Measuring electric power. Measurement uncertainty. Measurement error: a rough mistake, systematic error, random errors. Measurement uncertainty: The standard measurement uncertainty, Type ‘’A’’, Type ‘’B’’. Combined measurement uncertainty, Expanded measurement uncertainty.