Mantracourt Electronics Limited
– ICA User Manual
19
Chapter 7 Glossary
AWG
American Wire Gauge
Background Noise
The total noise floor from all sources of interference in a measurement system,
independent of the presence of a data signal. (See Noise)
Bipolar
The ability of a signal conditioner to display both positive and negative readings
Bridge Resistance
The resistance measured across the excitation terminals of a Strain Gauge.
Calibration
Adjustment of an instrument or compiling a deviation chart so that its reading
can be correlated to the actual value being measured
CMR
(Common-Mode
Rejection)
The ability of an instrument to eliminate the effect of AC or DC noise between
signal and ground. Normally expressed in dB at DC to 60 Hz. One type of CMR is
specified between SIG LO and PWR GND. In differential meters, a second type of
CMR is specified between SIG LO and ANA GND (METER GND)
Common Mode
Rejection Ratio
The ability of an instrument to reject interference from a common voltage at its
input terminals with relation to ground. Usually expressed in dB (decibels).
Drift
Change of a reading/set point value over periods due to several factors including
change in ambient temperature, time and line voltage
Excitation
The external application of electrical voltage current applied to a transducer for
normal operation
Fine Adjustment
Zero and Span calibration have a Fine Adjustment to give accuracy to the
calibration. These are potentiometers
S
and
Z
for Span and Zero respectively
Full Bridge
A Wheatstone Bridge configuration utilizing four active elements or Strain
Gauges
Full Range Output
The algebraic difference between the minimum output and maximum output.
Gain
Gain is otherwise identified as SPAN. It relates to the proportional output to the
sensor input. Calibration of the ICA is determined by setting the Gain (Span) and
Offset (Zero). The amount of amplification used in an electrical circuit
Ground
The electrical neutral line having the same potential as the surrounding ground
Linearity
The closeness of a calibration curve to a specified straight line. Linearity is
expressed as the maximum deviation of any calibration point on a specified
straight line during any one calibration cycle
Load
The electrical demand of a process expressed as power (watts), current (amps) or
resistance (ohms)
Load Impedance
The impedance presented to the output terminals of a transducer by the
associated external circuitry
Load Cell
The load cell is one of a series of STRAIN GAUGE sensors that the ICA input is
designed to accept. (Torque Sensor, Pressure & temperature transducers)
Millivolt
One thousandth of a volt, 10
-3
volts symbol mV
Noise
An unwanted electrical interference on the signal wires
Null
A condition, such as balance, which results in a minimum absolute value of
output
Offset
Offset is otherwise identified as ZERO. Calibration of the ICA is determined by
setting the Offset (Zero) and Gain (Span)
Potentiometer
Two potentiometers (variable resistors) are used for fine calibration
Pressure
Transducer
The Pressure Transducer is one of a series of Strain Gauge sensors that the ICA
input is designed to accept. (Torque Sensor, Load Cell and Temperature
Transducers)
Proportional
Outputs
The Voltage or Current outputs are calibrated to be directly proportional to the
input from the sensor. The output is, within the sensor limits, taken as linear and
no linearity compensation is required within the ICA
Resolution
The input corresponding to a one-unit change in the least significant digit of the
data acquisition/display equipment (Good resolution is not necessarily equal to
good accuracy.)
