Lesson 4 Flashcards
A conformity to an indicated, standard, or true value, usually expresssed as a percentage deviation from the indicated, standard, or true value is know as ____.
Accuracy
The process of adjusting an instrument or compiling a deviation chart so that its reading can be correlated to the actual value being measured is know as a ___ procedure.
Calibration
The change through which the input to an instrument can be varied without initiating an instrument response is called an instrument’s ____.
Dead band
The departure from a desired value; the system deviation that exists after the process has been stabilized is known as ___. A transmitter may also have this characteristic.
deviation
The ratio of change in output divided by the change in an input that caused it is called ___.
Gain
The difference between upscale and downscale results in instrument response, when subjected to the same input approached from opposite directions, is known as a ___ error.
hysteresis
____ is the closeness of a calibration curve to a specified, straight line, which is expressed as the maximum deviation of any calibration point on a specified, straight line during any one calibration cycle.
Linearity
A signal path; a combination of two or more instruments or control functions arranged so that signals pass from one to another for the purpose of measurement and/or control, is known as a ____.
loop
The degree of refinement of a measurement, which depends on the sensitivity of the instrument and observation factors, and is typically expressed in the smallest measurement units available is known as ____.
Precision
The array of values a transmitter is intended to measure is called the ___ of the instrument.
range
The ability of a transmitter to reproduce output readings when exactly the same measured value is applied to it consecutively, under the same conditions, and approaching from the same direction is called ___ and is expressed as the maximum difference between two readings.
repeatability
The difference between the upper and lower limits of a transmitter range that is expressed in the same units as the range of the device is called the instrument’s ____.
Span
Instrument errors identified as an output signal that does not reflect 100% of the expected output signal or does not follow the input span is called ____.
Span Error
A change resulting from an error that is the same throughout the scale is called a ____ error.
Zero-shift
The operation of an automatic control process is dependent upon the ___ of each instrument in the loop.
Accuracy
The safety and proper operation of a controlled process is dependent upon what?
A correctly calibrated instrument
A transmitter is calibrated by using the appropriate input and output ____.
Standards
When an instrument is properly calibrated, its input is a ____ of its output so that the % input span is equal to its ____ output span.
Direct representation; percent
Accuracy is usually expressed as a percentage of the transmitter _____.
Span
Gain is the term for how much a ____ should change given the same ____ change.
output; input
A precise instrument will record an identical ____ signal each time an identical ____ is applied.
output; input
____ are used which establish guidelines for acceptable instrument calibration.
Standards
____ equipment should always be used to calibrate instruments.
Certified test
Certified test equipment can be obtained by having the test equipment compared and calibrated to a ____ test instrument that meets known standards.
certified
The calibrate any instrument, the ____ in the instrument must be identified.
errors
Instrument errors are ____ by comparing the measured output of a device to the expected output of the device.
identified
List the five most common instrument errors that may be identified by recording an instrument’s output signal with respect to its input.
zero-shift; span-error; non-linearlity; dead band; hysteresis
