TCI Scales Glossary

A/D (Analog to Digital)
Analog-to-digital conversion is an electronic process in which a continuously variable (analog) signal is changed, without altering its essential content, into a multi-level (digital) signal.

ACCUMULATOR
A register used to contain the results of an arithmetic or logical operation

ACCURACY
The degree to which the result of a measurement, calculation, or specification conforms to the correct value or a standard.

AMBIENT CONDITIONS
The conditions (humidity, pressure, temperature, etc.) of the medium surrounding the load cell.

AMPERE
A unit of electric current equal to a flow of one coulomb per second.

ANALOG
Relating to or using signals or information represented by a continuously variable physical quantity such as spatial position or voltage.

ANGULAR LOAD, CONCENTRIC (Common Center)
A load applied concentric with the primary axis at the point of application, and at some angle with respect to the primary axis.

ANGULAR LOAD, ECCENTRIC (Off Center)
A load applied eccentric with the primary axis at the point of application and at some angle with respect to the primary axis.

ASCII (American Standard Code for Information Interchange)
A character-encoding scheme originally based on the English alphabet that encodes 128 specified characters.

ASYNCHRONOUS TRANSMISSION
Transmission of data, generally without the use of an external clock signal, where data can be transmitted intermittently rather than in a steady stream.

AXIAL LOAD
A load applied along a line of an axis.

BAUD
A unit of transmission speed equal to the number of times a signal changes state per second. For one baud is equivalent to one bit per second.

BCD (Binary Coded Decimal)
A class of binary encodings of decimal numbers where each decimal digit is represented by a fixed number of bits

BEZEL
A holder designed for the edges of a lens, window, or display.

BIDIRECTIONAL
Functioning in two directions.

BIT
A unit of information expressed as either a 0 or 1 in binary notation.

BLACKOUT
A failure of eletrical power supply.

BOARD OF GOVERNORS
National Conference on Weights and Measures body of officials that sets NTEP policy and has final say in disputes.

BROWNOUT
A reduction in or restriction on the availability of electrical power in a particular area.

CALIBRATE
Correlate the readings of (an instrument) with those of a standard in order to check the instrument's accuracy.

CAPACITANCE
The ability of a system to store an electric charge.

CERMET
Any of a class of heat-resistant materials made of ceramic and sintered metal.

CHECK RODS
Rods installed to prevent a vessel or other weighing system component from gross tipping or extended travel.

CHECKWEIGHER
Automatic or manual machine for checking the weight of packaged commodities.

CLASS III
Classes of scales used in commercial weighing not otherwise specified.

CMOS (Complementary Metal Oxide Semiconductor)
A technology for making low power integrated circuits.

CURRENT LOOP
A serial transmission method that uses a closed loop.

CC (NTEP Certificate of Conformance)
Certification that a device meets all applicable requirements of Handbook 44.

COMBINED ERROR (Non-linearity and Hysteresis)
The maximum deviation from the straight line drawn between original no-load and rated load outputs of a transducer output due to non-linearity (increasing load) and hysteresis (decreasing load).

COMPENSATION
The utilization of supplementary devices, materials, or processes to minimize known sources of error.

COMPRESSION
A force applied to a strain gauge that causes the gauge wires to compress and their cross sectional area to increase, thus decreasing the gauge resistance.

CONFORMAL COATING
Material that is applied to electronic circuitry to act as protection against moisture, dust, chemicals, and temperature extremes that, if uncoated (non-protected), could result in damage or failure of the electronics to function.

CPU (Central Processing Unit)
The computer module or chip that controls fetching, decoding and executing instructions; essentially the brains of the computer.

CREEP
The gradual change in load cell output occurring with time, while under load, and with all environmental conditions and other variables remaining constant.

DEAD LOAD
The intrinsic weight of a structure or vehicle, excluding the weight of passengers or goods.

DEFLECTION
The change in length along the Primary Axis of the load cell between no-load and Rated Load conditions.

DIGITAL
Expressed as series of the digits 0 and 1, typically represented by values of a physical quantity such as voltage or magnetic polarization.

DIP (Dual Inline Package)
Dual in-line package, a package for an integrated circuit consisting of a rectangular sealed unit with two parallel rows of downward-pointing pins.

DOT MATRIX
A grid of dots that are filled selectively to produce an image on a screen or paper.

ECCENTRIC LOAD
Any load applied parallel to, but not concentric with, the Primary Axis.

EEPROM (Electrically Erasable Programmable Read Only Memory)
A read-only memory whose contents can be erased and reprogrammed using a pulsed voltage.

ELECTRIC CURRENT
A flow of electric charge. In electric circuits this charge is often carried by moving electrons in a wire.

ELECTRICAL NOISE
A random fluctuation in an electrical signal, a characteristic of all electronic circuits.

ELECTRON
A stable subatomic particle with a charge of negative electricity, found in all atoms and acting as the primary carrier of electricity in solids.

ELECTROSTATIC CHARGE
An electric charge on the surface of an insulated object.

EMI (Electromagnetic Interference)
Disturbance that affects an electrical circuit due to either electromagnetic induction or electromagnetic radiation emitted from an external source.

EPROM (Erasable Programmable Read Only Memory)
A read-only memory whose contents can be erased by ultraviolet light or other means and reprogrammed using a pulsed voltage.

ERROR
A measure of the estimated difference between the observed or calculated value of a quantity and its true value.

EXCITATION
The application of energy to a particle, object, or physical system, in particular.

FULCRUM
The point on which a lever rests or is supported and on which it pivots.

FULL DUPLEX
A communications device or channel that is capable of simultaneous transmission in both directions.

GRADUATION
A mark on an instrument or vessel indicating degrees or quantity.

HALF DUPLEX
Allowing the transmission of signals in both directions but not simultaneously.

HANDSHAKING
Process by which two devices, such as modems, initiate communication with each other in order to establish a session, in which the devices can exchange any desired information.

HERMETICALLY SEALED
Impervious to air or gas; an airtight seal.

HYSTERESIS
The phenomenon in which the value of a physical property lags behind changes in the effect causing it.

INTERFACE
A device or program enabling a user to communicate with a computer.

J-BOX (Junction Box)
A container for electrical connections, usually intended to conceal them from sight and deter tampering.

LED (Light Emitting Diode)
Light-emitting diode, a semiconductor diode that glows when a voltage is applied.

LEVER
A rigid bar resting on a pivot, used to help move a heavy or firmly fixed load with one end when pressure is applied to the other.

LIVE LOAD
The load applied to a scale that is being measured by the weighing system.

LOAD
The weight or force applied to the load cell.

LOAD CELL
A transducer that is used to convert a force into an electrical signal.

MASS
The quantity of matter that a body contains, as measured by its acceleration under a given force or by the force exerted on it by a gravitational field.

METAL FILM RESISTOR
A resistor constructed by applying a thin film of metal onto a substrate of ceramic or glass.

MOTION DETECTION
A circuit used in an indicator to sense when the displayed weight data is changing at a greater rate than preset limits (or is unstable) and to inhibit certain functions during this time. Functions inhibited may be data output, entry of a push-button auto zero, entry of an auto tare value or activation of zero tracking.

NEMA National Electrical Manufacturers Association. NCWM (National Conference on Weights and Measures)
An association of state and local officials. Federal and industry representatives that adopt uniform (model) laws and regulations (e.g., NIST Handbook 44).

NIST (National Institute for Standards and Technology)
An agency of the federal government to which all precision measurements are traceable. Formerly the National Bureau of Standards (NBS)

NOMINAL LOAD CAPACITY
The designed normal maximum load cell capacity.

NONLINEARITY
The behavior of a circuit, particularly an amplifier, in which the output signal strength does not vary in direct proportion to the input signal strength.

NONVOLATILE MEMORY
Solid state memory that does not need to have its memory contents periodically refreshed.

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.

OEM (Original Equipment Manufacturer)
A manufacturer who produces equipment for use or inclusion by another manufacturer in its product.

OHM
The SI unit of electrical resistance, expressing the resistance in a circuit transmitting a current of one ampere when subjected to a potential difference of one volt.

OHM’S LAW
Relationship between the potential difference (voltage), electric current, and resistance in an electric circuit.

OUTPUT
A place where power or information leaves a system.

OVERLOAD RATING
The maximum load, in percent of Rated Capacity, which can be applied without producing a permanent shift in performance characteristics or 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.

PARALLEL CIRCUIT
A closed circuit in which the current divides into two or more paths before recombining to complete the circuit.

PARALLEL COMMUNICATIONS
A method of conveying multiple binary digits (bits) simultaneously. In contrast to serial communication which only acts upon one bit at a time.

PARITY
A function whose being even (or odd) provides a check on a set of binary values.

POISE
A moveable weight that counterbalances the load on a scale.

PORT
A socket in a computer or network into which a device can be plugged.

POTENTIOMETER
A variable resistor with a third adjustable terminal.

PRIMARY AXIS
The axis along which the load cell is designed to be loaded; normally its geometric center line.

RAM (Random Access Memory)
Allows data items to be read and written in roughly the same amount of time regardless of the order in which data items are accessed.

REACTANCE
The nonresistive component of impedance in an AC circuit

REPEATABILITY
The ability of an instrument, system, or method to give identical results in successive instances.

RESISTANCE
The degree to which a substance or device opposes the passage of an electric current, causing energy dissipation.

RESISTIVITY
A measure of the resisting power of a specified material to the flow of an electric current.

RFI (Radio Frequency Interference)
Electromagnetic radiation which is emitted by electrical circuits carrying rapidly changing signals, as a by-product of their normal operation, and which causes unwanted signals (interference or noise) to be induced in other circuits.

ROM (Read Only Memory)
Memory read at high speed but not capable of being changed by program instructions.

RS-232
A standard for serial communications.

SCALE
An instrument for weighing.

SERIAL TRANSMISSION
Sequential transmission of data one bit at a time.

SIDE LOAD
Any load acting 90° to the primary axis at the point of axial load applications.

SIP (Signal In-Line Package)
IC package that has a single row of leads protruding from the bottom of its body.

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 set of storage locations that store data in such a way that the most recently stored item is the first to be retrieved.

STRAIN GAUGE
A device for indicating the strain of a material or structure at the point of attachment.

TARE
An allowance made for the weight of the packaging in order to determine the net weight of goods.

TEMPERATURE COEFFICIENT
Relative change of a physical property when the temperature is changed by 1 Kelvin.

TEMPERATURE RANGE, Safe
The extremes of temperatures within which the load cell will operate without permanent adverse change to any of its performance characteristics.

TOLERANCE
An allowable amount of variation of a specified quantity, especially in the dimensions of a machine or part.

TRANSDUCER
A device that converts variations in a physical quantity, such as pressure or brightness, into an electrical signal, or vice versa

TRANSIENT
A momentary variation in current, voltage, or frequency.

TRIAC
A three-electrode semiconductor device that will conduct in either direction when triggered by a positive or negative signal at the gate electrode.

VOLATILE MEMORY
Computer memory that requires power to maintain the stored information.

VOLT
The SI unit of electromotive force, the difference of potential that would drive one ampere of current against one ohm resistance.

VOLTAGE
An electromotive force or potential difference expressed in volts.

VOLTAGE DIP
A short duration reduction in voltage which can be caused by a short circuit, overload or starting of electric motors.

VOLTAGE SPIKE
Fast, short duration electrical transients in voltage, current, or transferred energy in an electrical circuit.

WATER TIGHT
Closely sealed, fastened, or fitted so that no water enters or passes through.

WEATHER PROOF
Resistant to the effects of bad weather, especially rain.

WEIGHT
A body's relative mass or the quantity of matter contained by it, giving rise to a downward force; the heaviness of a person or thing.

ZERO STABILITY
The degree to which the load cell maintains its Zero Balance with all environmental conditions and other variables remaining constant.