Glossary of Terms

Glossary of Terms for the Scale Industry

Click here to return to the Glossary of Terms search section.

F

Flexures
Thin steel or plastic bands or plates which replace the pivots and bearings of a conventional scale thus allowing less movement and reducing friction.

FM
Factory Mutual Research Corporation. An organization which sets industrial safety standards.

Forced Vibration
Vibration of a system caused by an imposed force. Steady-state vibration is an unchanging condition of periodic or random motion.

Full Bridge
A Wheatstone bridge configuration utilizing four active elements or strain gages.

Full-Scale
Maximum level that can be measured. For example, in analog input circuit maximum allowable voltage or current level is called full scale because any increase beyond that level cannot be measured.

G

Gain-in-Weight Batching
Device used to measure preset amount of material by discharging material into container, hopper, or vessel positioned on scale.

Graduation
A mark or an instrument or vessel indicating degrees or quantity.

Gram
A metric unit of weight equal to 1000 milligrams.

Gross Weight
Total weight of commodity, including weight of packaging or container

H

Handbook 44 (H-44)
A comprehensive set of requirements for weighing and measuring devices that are used in commerce and law enforcement activities; not a Federal law but developed by the National Conference of Weight and Measures. Its complete title is "Specifications, Tolerances, and Other Technical Requirements for Weighing and Measuring Devices."

Handbook 44 has been adopted by all 50 states as the basis for exercising their control of commercial weighing and measuring devices.

Handshake
An interface procedure that is based on status/data signals that assure orderly data transfer as opposed to asynchronous exchange.

Headload
Force or pressure exerted on process equipment by weight of material in supply hopper.

Hysteresis
Hysteresis causes the difference in the output of a sensor when the direction of the input has been reversed. This produces error and so affects the accuracy of a device. This is shown here in graphical form. The input to the sensor, the measurand, is increased in set increments.

Towards the end of its range, the measurand is decreased in similar sized decrements. The graph shows the difference in the output of the sensor when the measurand value is increasing to when it is decreasing. This is the hysteresis of the system.

Not all sensors or measurement systems suffer from hysteresis. It is caused by various factors, particularly mechanical strain and friction. Slack motion in gear systems and screw threads (often referred to as backlash) is also a common cause.

Hence measurement systems likely to suffer significantly from hysteresis may incorporate mechanical gears or bearings, or other moving parts, and materials that tend to be elastic, such as rubber, plastics, and some metals.

Note: Measurements should be made in a manner which minimizes the effects of creep, typically done by conducting the test as rapidly as possible.

I

Icon
A graphic functional symbol display. A graphic representation of a function or functions to be performed by the computer.

Indicating Instrument
Measuring instrument in which value of measured quantity is visually indicated.

Input
1) Data to be processed. 2) State or sequence of states occurring on specified input channel. 3) Device or collective set of devices used for bringing data into another device. 4) Channel for impressing state on device or logic element. 5) Process of transferring data from external device to internal device.

Interface
1) The means by which two systems or devices are connected and interact with each other. 2) (verb) Logic necessary to provide electrical and communication compatibility between two devices. 3) (noun) Shared boundary. 4) A change in a transmission medium which affects the sound energy. Examples: 20 mA current loops, RS-232C, RS-422, RS-485, Allen-Bradley RIO, and Modbus RTU.

International Standards Organization (ISO)
The standards organization that developed the Open Systems Interconnect Model and other international communications standards.

Intrinsic Safety
Design technique applied to electrical equipment and wiring for hazardous locations. Based on limiting electrical and thermal energy to level below that required to ignite hazardous atmospheric mixtures.

Intrinsically Safe
An instrument which will not produce any spark or thermal effects under normal or abnormal conditions that will ignite a specified gas mixture.

ISO
International Standards Organization.

J

K

Kilogram
A metric unit of weight or measurement equal to 1000 grams.

L

LCD
Liquid Crystal Display. Reflective visual readout device commonly used in digital watches and laptop computers.

LED
Light-Emitting Diode.

Lever
A tool that transfers force equally with reduction or multiplication.

Live Load
Design capacity of vessel or load applied to scale base, which is actually being measured by weighing system.

Load
The weight or force applied to the load cell.

Load Buttons
The spherical like shape of the top surface of a load cell where the load is applied.

Load Cell
A device which produces an output signal proportional to the applied weight or force.

Load Impedance
The impedance presented to the output terminals of a transducer by the associated external circuitry.

Click here to return to the Glossary of Terms search section.