Lesson 4

Question 1

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 ____.

Answer 1

Accuracy

Question 2

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.

Answer 2

Calibration

Question 3

The change through which the input to an instrument can be varied without initiating an instrument response is called an instrument’s ____.

Answer 3

Dead band

Question 4

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.

Answer 4

deviation

Question 5

The ratio of change in output divided by the change in an input that caused it is called ___.

Answer 5

Gain

Question 6

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.

Answer 6

hysteresis

Question 7

____ 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.

Answer 7

Linearity

Question 8

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 ____.

Answer 8

loop

Question 9

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 ____.

Answer 9

Precision

Question 10

The array of values a transmitter is intended to measure is called the ___ of the instrument.

Answer 10

range

Question 11

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.

Answer 11

repeatability

Question 12

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 ____.

Answer 12

Span

Question 13

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 ____.

Answer 13

Span Error

Question 14

A change resulting from an error that is the same throughout the scale is called a ____ error.

Answer 14

Zero-shift

Question 15

The operation of an automatic control process is dependent upon the ___ of each instrument in the loop.

Answer 15

Accuracy

Question 16

The safety and proper operation of a controlled process is dependent upon what?

Answer 16

A correctly calibrated instrument

Question 17

A transmitter is calibrated by using the appropriate input and output ____.

Answer 17

Standards

Question 18

When an instrument is properly calibrated, its input is a ____ of its output so that the % input span is equal to its ____ output span.

Answer 18

Direct representation; percent

Question 19

Accuracy is usually expressed as a percentage of the transmitter _____.

Answer 19

Span

Question 20

Gain is the term for how much a ____ should change given the same ____ change.

Answer 20

output; input

Question 21

A precise instrument will record an identical ____ signal each time an identical ____ is applied.

Answer 21

output; input

Question 22

____ are used which establish guidelines for acceptable instrument calibration.

Answer 22

Standards

Question 23

____ equipment should always be used to calibrate instruments.

Answer 23

Certified test

Question 24

Certified test equipment can be obtained by having the test equipment compared and calibrated to a ____ test instrument that meets known standards.

Answer 24

certified

Question 25

The calibrate any instrument, the ____ in the instrument must be identified.

Answer 25

errors

Question 26

Instrument errors are ____ by comparing the measured output of a device to the expected output of the device.

Answer 26

identified

Question 27

List the five most common instrument errors that may be identified by recording an instrument’s output signal with respect to its input.

Answer 27

zero-shift; span-error; non-linearlity; dead band; hysteresis