E1BGLOSS 09/14/2010
11:19:49 Page 578
Glossary
A/D converter A device that converts analog voltages
into a digital numbers.
absolute temperature scale A temperature scale
referenced to the absolute zero of temperature;
equivalent to thermodynamic temperature.
accelerometer An instrument for measuring acceleration.
accuracy The closeness of agreement between the
measured value and the true value.
actual flow rate Flow rate specified under the actual
temperature and pressure conditions of the
measurement. See standard flow rate.
actuator Device that creates a desired linear or rotary
motion; classes generally include electrical,
mechanical, hydraulic or pneumatic.
advanced-stage uncertainty The uncertainty estimate
beyond the design-stage that includes the uncertainty
due to measurement system, measurement procedure,
and measured variable variation.
alias frequency A false frequency appearing in a
discrete data set that is not in the original signal.
amplitude Characteristic of a signal or component
frequency of a signal that expresses a range of timedependent magnitude variations.
apparent strain A false output from a strain gauge as a
result of input from extraneous variables such as
temperature.
astable multivibrator Switching circuit that toggles on
or off continuously in response to an applied voltage
command.
band-pass filter A device that allows a range of signal
frequencies to pass unaltered, while frequencies
outside this range, both higher and lower, are
attenuated.
Bessel filter Filter design having a maximally linear
phase response over its passband.
bias An offset value.
bias error See systematic error. Archaic term no longer
used in measurements.
bimetallic thermometer A temperature measuring
device that utilizes differential thermal expansion of
two materials.
bistable multivibrator See flip-flop.
bit The smallest unit in binary representation.
bit number The number of bits used to represent a word
in a digital device.
bonded resistance strain gauge A strain sensor that
exhibits an electrical resistance change indicative of
strain. The sensor is bonded to the test specimen in
such a way that the gauge accurately measures the
strain at the surface of the test specimen.
bridge constant The ratio of the actual bridge voltage to
the output of a single strain gauge sensing the
maximum strain.
buffer Memory set aside to be accessed by a specific
I/O device, such as to temporarily store data.
bus A major computer line used to transmit information.
Butterworth filter Filter design having a maximally
flat magnitude ratio over its passband.
byte A collection of 8 bits.
calibration Act of applying a known input value to a
system so as to observe the system output value.
calibration curve Plot of the input values versus the
output values resulting from a calibration.
central tendency Tendency of data scatter to group
about a central (mean or most expected) value.
charge amplifier Amplifier used to convert a high
impedance charge into a voltage.
circular frequency Frequency specified in radians per
second; angular frequency.
closed-loop control Type of control action that is
based on the output value from a sensor relative to a
set-point.
combined standard uncertainty Uncertainty estimate
that includes both systematic and random standard
uncertainties.
common-mode voltage Voltage difference between two
different ground points. See ground loop.
concomitant method An alternate method to assess a
value of a variable.
conduction error Error in temperature measurement
caused by the diffusion of heat through a temperature
sensor either to or away from the measuring
environment so as to change the sensor temperature.
confidence interval Interval that defines the limits
about a mean value within which the true value is
expected to fall.
confidence level Probability that the true value falls
within the stated confidence interval.
control A means to set and maintain a value during a test.
control parameter Parameter whose value is set during
a test and that has a direct effect on the value of the
measured variable.
conversion error The errors associated with converting
an analog value into a digital number.
conversion time The duration associated with
converting an analog value into a digital number.
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11:19:49 Page 578
Glossary
A/D converter A device that converts analog voltages
into a digital numbers.
absolute temperature scale A temperature scale
referenced to the absolute zero of temperature;
equivalent to thermodynamic temperature.
accelerometer An instrument for measuring acceleration.
accuracy The closeness of agreement between the
measured value and the true value.
actual flow rate Flow rate specified under the actual
temperature and pressure conditions of the
measurement. See standard flow rate.
actuator Device that creates a desired linear or rotary
motion; classes generally include electrical,
mechanical, hydraulic or pneumatic.
advanced-stage uncertainty The uncertainty estimate
beyond the design-stage that includes the uncertainty
due to measurement system, measurement procedure,
and measured variable variation.
alias frequency A false frequency appearing in a
discrete data set that is not in the original signal.
amplitude Characteristic of a signal or component
frequency of a signal that expresses a range of timedependent magnitude variations.
apparent strain A false output from a strain gauge as a
result of input from extraneous variables such as
temperature.
astable multivibrator Switching circuit that toggles on
or off continuously in response to an applied voltage
command.
band-pass filter A device that allows a range of signal
frequencies to pass unaltered, while frequencies
outside this range, both higher and lower, are
attenuated.
Bessel filter Filter design having a maximally linear
phase response over its passband.
bias An offset value.
bias error See systematic error. Archaic term no longer
used in measurements.
bimetallic thermometer A temperature measuring
device that utilizes differential thermal expansion of
two materials.
bistable multivibrator See flip-flop.
bit The smallest unit in binary representation.
bit number The number of bits used to represent a word
in a digital device.
bonded resistance strain gauge A strain sensor that
exhibits an electrical resistance change indicative of
strain. The sensor is bonded to the test specimen in
such a way that the gauge accurately measures the
strain at the surface of the test specimen.
bridge constant The ratio of the actual bridge voltage to
the output of a single strain gauge sensing the
maximum strain.
buffer Memory set aside to be accessed by a specific
I/O device, such as to temporarily store data.
bus A major computer line used to transmit information.
Butterworth filter Filter design having a maximally
flat magnitude ratio over its passband.
byte A collection of 8 bits.
calibration Act of applying a known input value to a
system so as to observe the system output value.
calibration curve Plot of the input values versus the
output values resulting from a calibration.
central tendency Tendency of data scatter to group
about a central (mean or most expected) value.
charge amplifier Amplifier used to convert a high
impedance charge into a voltage.
circular frequency Frequency specified in radians per
second; angular frequency.
closed-loop control Type of control action that is
based on the output value from a sensor relative to a
set-point.
combined standard uncertainty Uncertainty estimate
that includes both systematic and random standard
uncertainties.
common-mode voltage Voltage difference between two
different ground points. See ground loop.
concomitant method An alternate method to assess a
value of a variable.
conduction error Error in temperature measurement
caused by the diffusion of heat through a temperature
sensor either to or away from the measuring
environment so as to change the sensor temperature.
confidence interval Interval that defines the limits
about a mean value within which the true value is
expected to fall.
confidence level Probability that the true value falls
within the stated confidence interval.
control A means to set and maintain a value during a test.
control parameter Parameter whose value is set during
a test and that has a direct effect on the value of the
measured variable.
conversion error The errors associated with converting
an analog value into a digital number.
conversion time The duration associated with
converting an analog value into a digital number.
578