Rice Lake Weigh Modules/Mount Assemblies - Manual (Page 82)

GLOSSARY
G-6
REMOTE SENSING
A method of regulating the excitation voltage to
the load cells. Some indicators compensate for
voltage drops occurring between the indicator
and load cells by increasing the indicator
excitation output voltage; other indicators
compensate for this voltage drop by amplifying
the load cell return signal.
REPEATABILITY
The maximum difference between load cell
output readings for repeated loadings under
identical loading and environmental conditions;
the ability of an instrument, system, or method
to give identical performance or results in
successive instances.
RESISTANCE
Opposition to current flow offered by a purely
resistive component; simple opposition to
current flow. Measured in ohms. See REAC-
TANCE.
RESISTIVITY
The electrical resistance offered by a unit cube
of material to the flow of direct current
between opposite faces of the cube. It is
measured in “ohm-centimeters.”
RESOLUTION
The smallest change in mechanical input which
produces a detectable change in the output
signal.
RFI (Radio Frequency Interference)
Radio frequency energy of sufficient magnitude
to possibly affect operation of other electrical
equipment.
ROM (Read Only Memory)
A memory unit in which instructions or data
are permanently stored for use by the machine
or for reference by the user. The stored
information is read out non-destructively and
no information can subsequently be written
into the memory.
RS-232
A voltage-based serial method of data commu-
nication used to transfer data between digital
devices. Two wires carry the data; one wire is
signal ground, and several control wires may be
used for handshaking. A logic “high” is from -3
to -25 volts and a logic “low” is from +3 to +25
volts. Transmission distance should be
restricted to 50 feet.
S
SAFETY FACTOR
A figure denoting the overload (and allowance
thereof) a device can withstand before breaking
down.
SCALE
A device for weighing, comparing and
determining weight or mass.
SENSITIVITY
The ratio of the change in output to the change
in mechanical input.
SERIAL TRANSMISSION
A method of data transmission in which each
bit of information is sent sequentially on a
single channel.
SETPOINT
In a feedback control loop, the point which
determines the desired value of the quantity
being controlled.
SHEAR BEAM
A bending beam load cell in which the strain
gauges are mounted on a thin web of material
in a machined-out cavity in the load cell.
SHIFT TEST
A test intended to disclose the weighing
performance of a scale under off-center loading.
SIDE LOAD
Any load acting 90
°
to the primary axis at the
point of axial load applications.
SIGNAL TRIM
A method of matching load cell outputs in a
multicell system by adjusting the output signal
voltage through a variable resistor placed
across the signal leads.
SIP (Signal In-Line Package)
A flat, molded component package having
terminal lugs along one side; half of a dual in-
line package (DIP).
SPAN
The difference between the highest value and
the lowest value.
STABILIZATION PERIOD
The time required to ensure that any further
change in the parameter being measured is
tolerable.
STACK
A temporary storage area in a computer
memory consisting of a small group of
registers. Data stored in the stack is retrieved
from the stack in reverse order in which it is
stored.
STANDARD TEST CONDITIONS
The environmental conditions under which
measurements should be made, when
measurements under any other conditions may
result in disagreement between various
observers at different times and places. The
conditions are as follows: Temperature: 72
° ±
3.6
°
F (23
° ±
2
°
C) Barometric Pressure: 28 to 32
inches Hg.
STATIC OVERLOAD CAPACITY
Capacity as a percentage of nominal load limit
capacity, in which the load cell can safely be
loaded to this limit with no adverse affect on
the performance or any change in its zero
balance or other specifications.
STAY RODS
Rods installed to rigidly restrain a vessel or
other weighing system component in the
horizontal position. They will have little effect
on the accuracy of the system when installed
properly.
STRAIN GAUGE
A device for detecting the strain that a certain
force produces on a body. The gauge consists of
one or more fine wires cemented to the surface
under test. As the surface becomes strained,
the wires stretch or compress, changing their
resistance. Several strain gauges are used to
make up a load cell.
T
TARE
The weight of an empty container or vehicle, or
the allowance or deduction from gross weight
made on account thereof.
TEMPERATURE COEFFICIENT
A figure which states the extent to which a
quantity drifts under the influence of
temperature.
TEMPERATURE EFFECT , On Rated
Output
The change in rated output due to a change in
ambient temperature. Usually expressed as the
percentage change in rated output per 100
° F
change in ambient temperature.
TEMPERATURE EFFECT, On Zero
Balance
The change in zero balance due to a change in
ambient temperature. Usually expressed as the
change in zero balance in percent of rated
output per 100
° F change in ambient tempera-
ture.
TEMPERATURE RANGE, Compen-
sated
The range of temperatures over which the load
cell is compensated to maintain rated output
and zero balance within specific limits.
TEMPERATURE RANGE, Safe
The extremes of temperatures within which the
load cell will operate without permanent
adverse change to any of its performance
characteristics.