L1 Flashcards
Over the last century and a half, art of measuring electrical quantities
Analog
The principal effort was aimed at deflection-type instrument with a scale and movable pointer.
Analog
The angle of deflection of the pointer is function of, and is therefore analogous to, the value of the electrical quantity being measured.
Analog
instrument was coined to identify deflection-type instruments and to distinguish these from totally different instruments, display in decimal (digital) from the value of the quantity being measured.
Analog
display in decimal (digital) from the value of the quantity being measured.
Digital instrument
newer instruments.
Digital instrument
Common purposes in supplying information about some variable quantity
that is to be measured.
Instrument
What function supplies information about some variable quantity
that is to be measured.
Indicating
Provides visual indication of the quantity
Instrument
Furnishes a permanent record.
Instrument
What function furnishes permanent record
Recording
Used to control quantity.
Instrument
What function is used to control quantity
Controlling
3 basic function
Indicating
Recording
Controlling
These entire system is called a
Control or automated system
What type of instrument uses the function of recording, and indicating?
General instrument
What type of instrument uses the function of controlling ?
Industrial instrument
What type of instrument is used to measure solution conductivity
Current sensitive devise
increase the signal of
the quantity being measured.
Electronic instrument that contains amplifying circuit
measure current, voltage, resistance, pressure, temperature, sound level or any other physical quantities.
Eletronic instrument
are more expensive than a simple electrical instrument, but they offer significant advantages for measurement purposes. It has higher sensitivity rating because it utilized electronic amplifiers.
Electronic instrument
What instrument has the ability to monitor remote signal
Electronic instrument
defined by international and maintained at Bureau of Weight and Measures in Paris.
International standard
represent certain units of measurement to the closest possible accuracy attainable by the science and technology of measurement.
International standard
-it applies at National Standards laboratories in different countries.
Primary standard
The National Bureau of Standards (NBS) is responsible for maintaining the primary standards are not available for use outside the national laboratories.
Primary standard
Their principal function is calibration and verification of secondary standards
Primary standard
are basic reference standards used by measurement and calibration laboratories in the industry to which they belong.
Secondary standard
Each of the laboratory is responsible to its own ?
Secondary standard
After the calibration the _________ _______ are returned to the industrial laboratory with a certification of measuring accuracy in terms of primary standard.
Secondary standard
are the principal tools of the measurements laboratory.
Working standard
They are used to check and calibrate the instruments used in the laboratory in the laboratory or to make comparison measurements in industrial application.
Working standard
convert non-electrical signals into electrical signal.
Transducer sensor
are required only if the quantity being measured is non-electrical signal such as pressure or temperature.
Transducer sensor
is required to process the incoming electrical signal to make it suitable for application to the indicating device.
Signal modifier
The signal may need to be amplified until it is of significant amplitude to cause change at the indicating device
Signal modifier
is a modifier design to reduce the strength of signal applied at the indicating device.
Voltage divider
Wave-shaping circuits such as rectifiers, filters and choppers are also used as modifiers
Signal modifier
are deflection type meter for such general-purpose instruments such as voltmeters, current meters or choppers
Indicating devise
is the process of comparing an unknown quantity with an accepted
standard quantity.
Measurement
It involves connecting a measuring instrument into the system under consideration and observing the resulting response on the instrument.
Measurement
The measurement thus obtained is quantitative measure of the so-called
True value
is used as a term for most the measurements because true-value is very difficult to define.
Expected value
are always made nearest to something whether it is stated or not, ______ is never exact.
Measurement
The degree to which a measurement conforms to the expected value
Error in measurement
Errors can be express either as
Absolute error / per cent of error
can be defined as the difference between the expected value and the measured value.
Absolute error
is considered to be one half of the smallest measuring unit.
Greatest possible error
Machines used in manufacturing often set “_______”, or “______ _____,” or “_____” in which product measurements will be tolerated or accepted before they are considered flawed.
Margin of error
Tolerance
Range
Any measurements within this range are “tolerated” or perceived as correct. This is also known as
Tolerance range
Any measurements within this range are “tolerated” or perceived as correct. This is also known as
Tolerance range
