Embedded Files
Definition measurement :
Measurement is the process of determining the amount, degree or capacity by comparing with the accepted standards of the system units being used.
Standard is the physical form of the unit of measurement as well as that of its submultiple or multiple value.
Measuring Instrument is the device used for comparing the unknown quantity with the unit of measurement or a standard quantity.
Definition Instrument :
Instrument is a device or mechanism used to determine the
value or magnitude of a quantity under observation.
Electronic instrument is a device that based on electrical or
electronic principles for its measurement functions.
Instrumentation system is a physical system, which is
collection of physical objects connected in such a way to give the desired output response. May be defined as an assembly of
various instruments and other components interconnected to
measure, analyze and control the electrical, thermal, hydraulic
and other non-electrical physical quantities.
osiloscope
Direct measurement methods
Null measurement method :
measuring current and voltage more accurately by balancing the circuit so that no current flows through the measurement device
Standard measurements of voltage and current alter circuits, introducing numerical uncertainties. Voltmeters draw some extra current, whereas ammeters reduce current flow. Null measurements balance voltages, so there is no current flowing through the measuring device and the circuit is unaltered.
Null measurements are generally more accurate but more complex than standard voltmeters and ammeters. Their precision is still limited
Comparison methods
The unknown quantity is determined by direct comparison with a standard of the given quantity such as measurement of emf by comparison with the emf of a standard cell.
Include null method, differential method etc
Page updated
Google Sites
Report abuse