Glossary of Terms

Glossary of Terms for the Scale Industry

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C

Calibrate
1) Determine, usually by comparison with standard locations at which scale/chart graduations should be placed to correspond to series of values of quantity which instrument is to measure, receive, or transmit. 2) Adjust device output to bring it to desired value, within specified tolerance, for particular input value. 3) Determine error in device output by checking it against standard.

Calibration
1)Calibration refers to the units the scale of a sensor display or recorder is labeled in. 2)Process of presenting known quantity of material to be routinely measured to instrumentation system to determine functional relationship between device's input and output. Example: A type of sensor measuring the speed of a vehicle produces an electrical output. The size of this voltage is proportional to the speed of the vehicle. The speedometer pointer in the vehicle moves with respect to the voltage applied to it, but will be labeled in units of speed, not voltage. We therefore say the speedometer is calibrated in terms of speed. Note: There are two steps to weight calibration: Zero Calibration (zero live load) and Scale Factor calibration (span).

Calibration Curve
A record (graph) of the comparison of load cell outputs against standard test loads.

Cantilever Beam
A beam type load cell that has a machined-out center. The load sensing elements (strain gauges) are mounted on the inside perimeter of this machined center.

Capacitance
The ability of a component or material to store an electrostatic charge: measured in farads. Because the farad is a very large quantity, capacitance in electronic application is usually expressed in millionths of a farad (microfarads) or millionths of a farad (microfarads) or millionth of a millionth of a farad (pico farads).

Capacity
Maximum attainable volumetric or gravimetric flow rate from given piece or type of material handling equipment.

Cascading
Rate of slave feeder changes in direct proportion to change in master feeder.

Catch Sampling
Collecting and weighing material discharged from feeder over specified period of time to determine correction factors during calibration.

Center of Gravity (Mass Center)
The center of gravity of a body is that point in the body through which passes the resultant of weights of its component particles for all orientations of the body with respect to a uniform gravitational field.

Center Rod
Shaft that may be inserted in feed screw. Often used when feeding free-flowing materials or to add stability for heavy materials.

Cermet
An alloy of ceramic and metal, usually titanium carbide and nickel, used as a resistance element in some variable resistor; acronym of ceramic metal.

Character
One of set of elementary symbols which express information. Set usually includes decimal digits 0 through 9, letters A through Z, and special symbols used to denote functions.

Chassis
Hardware assembly that houses devices such as I/O modules, adapter modules, processor modules, and power supplies.

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

Checkweigher
A scale used to verify a predetermined weight within a prescribe limits.

Class III
Classes of scales used in commercial weighing not otherwise specified; grain test scale, retail precious metals and semi precious gem weighing, animal scales, postal scales, and scales used to determine laundry changes.

Class IIIL
Vehicle, axle-load, livestock, railway track scales, crane and hopper (other than grain hopper) scales.

CLC (Concentrated Load Capacity)
Maximum load designated by the manufacturer that can be placed anywhere on the platform of a vehicle, axle-load or livestock scale using the prescribed test pattern.

Clear
To restore a device to a prescribed initial state, usually the zero state.

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

Collecting Conveyor
Device used to gather and combine outputs of upstream equipment.

Combination Feeder
For weigh-belt equipment, any configuration involving mating of prefeeder to the weigh-belt to control flow of material to belt.

Communications Port
A connection on a terminal through which data is input and/or output.

Compatibility
Ability of devices to be interconnected and used without modification.

Com Port
An abbreviation for communications port, this generally refers to a serial port.

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

Compression
Stress caused by forces pushing together.

Compression Ratio
The ratio of the number of bits required to represent the original information to the number of bits required to represent the compressed signal.

Continuous
Process or part of process characterized by uninterrupted flow of production materials through time.

Control Panel
Panel which may contain instruments, controllers, or operator interface devices that allow operator to access and control plant operations.

Control Point
The point at which a system is to be maintained.

Counter Weight
A weight added to a body so as to reduce a calculated unbalance at a desired place.

CPU
Central processing unit. The part of the computer that contains the circuits that control and perform the execution of computer instructions.

Creep
The change in load cell signal occurring with time while under load and with all environmental conditions and other variables remain constant Note: Usually measured with rated load applied and expressed as a percent of rated output over a specific period of time.

Creep Recovery
The change in no-load signal occurring with time after removal of a load which had been applied for a specific period of time. Note: Usually measured over a specific time period immediately following removal of rated load and expressed as a percent of rated output.

CSA
Canadian Standard Association.

D/A Converter
Short for digital-to-analog converter. This is a device that changes a digitally coded word into its equivalent quantized analog voltage or current. Just like the A/D device, there are very high-speed D/A's available, capable of converting at data rates up to 1 GHz.

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