Rice Lake Weigh Modules/Mount Assemblies - Manual (Page 81)

G-5
GLOSSARY
NON-LATCHING RELAYS
Relays that will stay at the logic level based on
the current setpoint data. These relays will
“toggle” from energized to de-energized states
depending on the signal sent to them.
NON-LINEARITY
The maximum deviation of the calibration
curve from a straight line drawn between the
no-load and rated load outputs, expressed as a
percentage of the rated output and measured
on increasing load only.
NONVOLATILE MEMORY
A computer storage medium whose contents
remain unaltered when the power is switched
off; contents are available when power is
switched on again.
NTEP (National Type Evaluation
Program)
A program of cooperation between the National
Conference On Weights & Measures, NIST, state
weights and measures officials and the private
sector for determining conformance of weighing
equipment with the provisions of H-44.
O
OEM (Original Equipment
Manufacturer)
A manufacturer who produces equipment
for use or inclusion by another manufac-
turer in its product.
OHM
The unit of electrical resistance. The resistance
through which a current of one ampere will
flow when a voltage of one volt is applied.
OHM’S LAW
The relationship between current, voltage and
resistance. Current varies directly with voltage,
and inversely with resistance (I = E/R, where
I = Current, E = Voltage and R = Resistance).
OUTPUT
The signal (voltage, current, pressure, etc.)
produced by a load cell. Where the output is
directly proportional to excitation, the signal
must be expressed in terms such as Volts per
Volt, Millivolts per Volt, or Volts per Ampere,
etc., of excitation.
OUTPUT, Rated
The algebraic difference between the Outputs at
no-load and at Rated Load.
OVERLOAD RATING, Safe
The maximum load, in percent of Rated
Capacity, which can be applied without
producing a permanent shift in performance
characteristics beyond those specified.
OVERLOAD RATING, Ultimate
The maximum load, in percent of Rated
Capacity, which can be applied without
producing a structural failure.
OWM
Office of Weights and Measures at NIST.
OIML (International Organization of
Legal Metrology)
Treaty organization that recommends technical
requirements for weighing and measuring
equipment prior to the sale or distribution of a
model or type within the state, nation, etc.
P
PARALLEL CIRCUIT
A circuit in which the components are
connected across each other. The voltage
applied to each component is the same.
PARALLEL COMMUNICATIONS
Type of data communication in which all
elements in an information item (bits in a
word) are acted upon simultaneously, rather
than one at a time as in serial communications.
PARITY
A method of error checking where an extra bit
is sent to establish an even or odd number of
ones in the data of a character.
PAZ (Push-button Auto Zero)
Extension of the AZM function of a digital
weight indicator through the use of a front-
panel push-button.
POISE
A moveable weight that counterbalances the
load on a scale.
PORT
A point at which signals may be introduced to
or extracted from a circuit, device, or system.
POTENTIOMETER
A variable resistor employed as a voltage
divider.
POTTED CELL
A load cell which is environmentally sealed by
filling the strain gauge cavity with a material
that protects the gauges from environmental
hazards such as moisture. The potting material
must not interfere with normal strain gauge
movement, and allow the gauges to return to
their normal zero output position.
PREACT
Weight value which is set to allow for material
in suspension during a filling operation.
PRESSURIZATION
The process of supplying an enclosure with
clean air or an inert gas with or without
continuous flow at sufficient pressure to
prevent the entrance of combustible dust.
PRIMARY AXIS
The axis along which the load cell is designed to
be loaded; normally its geometric center line.
PROTECTIVE COMPONENT
A component or assembly which is so unlikely
to become defective in a manner that will lower
the intrinsic safety of the circuit that it may be
considered not subject to fault when analysis or
tests for intrinsic safety are made.
PURGING
The process of supplying an enclosure with
clean air or an inert gas at sufficient flow and
positive pressure to reduce, to an acceptable
safe level, the concentration of any flammable
gases or vapors initially present, and to
maintain this safe level by positive pressure
with or without continuous flow.
R
RACEWAY
An enclosed channel designed for holding
wires, cables, or busbars.
RAINPROOF
An enclosure so constructed, protected, or
treated, as to prevent rain from interfering with
the successful operation of the apparatus under
specified test conditions.
RAINTIGHT
An enclosure so constructed or protected that
exposure to a beating rain will not result in the
entrance of water under specified test
conditions.
RAM (Random Access Memory)
A data storage device that can be accessed in
any order. It is known as a read/write memory,
as information can be written into the memory,
then read out when needed by the microproces-
sor. The contents of RAM are lost when the
system is powered down.
REACTANCE
The opposition offered to the flow of alternating
current by pure capacitance, pure inductance,
or a combination of the two. Its unit is the
“ohm”.
REFERENCE STANDARD
A force-measuring device whose characteristics
are precisely known relative to a primary
standard.