Accuracy:
The ability to display a value that matches the ideal value for a known weight.
Balance:
A weighing machine. The terms scale and balance are often used interchangeably. Historically a balance was a device that determined mass by balancing an unknown mass against a known mass as with a 2 pan assay balance. In modern weighing machines balances are usually of the design that uses a force restoration mechanism to create a force to balance the force due to the unknown mass.
Baud Rate:
The speed of communication when using the RS-232 interface. The greater the number the faster the data is sent between 2 devices. Usually balances use 300 to 9600 baud.
Calibration:
The procedure to force the scale to display a certain value for a known standard mass. Then any other mass will be determined using the standard as the reference.
Capacity:
The maximum weight that can be placed on the scale or balance.
Checkweighing:
To compare a weight against limits to determine if the weight is within preset limits.
Density Determination:
Using a balance to determine the density of material, either solids or liquids. (Density is the grams/cubic centimetre). If a solid material is used it is weighed in the air and when suspended in a liquid. The density can be determined either manually or in some balances by using special software. To determine the density of a liquid a special float of known volume is weighed in air and in the liquid.
Eccentric Loading:
See Off Centre Loading.
Force Restoration:
A method to determine an unknown mass by balancing the force due to the mass with another force created by the system using coils mounted in a magnetic field. Also called Servo motor or force motor.
Increment:
These terms are often used interchangeably to indicate how well a scale displays the correct results. Increment is the value of the finest division of the scale. See also: Accuracy, readability, resolution.
Levelling:
The procedure to set the balance so the platform is horizontal. This gives the balance a position that is repeatable so the results will be the same if the balance is moved. This is done using levelling feet.
Linearity:
The ability of a scale or balance to show the correct value throughout the weighing range. Usually tested by placing known weights on the balance from near zero to full capacity.
Load Cell:
See Strain gauge load cell.
Mass:
Mass is a physical property of a material. The mass gives a material weight when gravity pulls the material toward earth. The units of mass are gram and kilogram. The terms mass and weight are often used interchangeably.
Menu:
A set of procedures that can be followed to change the characteristics of a balance. The menu is made up of a number of options, called parameters, that can be set at the factory or in some cases by the user.
Off Center Loading:
The ability to display the same value when a weight is placed anywhere on the weighing platform. Tested by weighing in the center of 4 quadrants on the platform. Also called eccentric loading or shift test.
Parameter:
See Menu.
Parts Counting:
Using a scale to determine the number of parts placed on the platform based upon the average piece weight. the piece weight is either entered by the user or determined by weighing a sample on the scales.
Readability:
These terms are often used interchangeably to indicate how well a scale displays the correct results. Readability is the value of the finest division of the scale. See also: accuracy, increment, resolution.
Repeatability:
The ability to display the same value when a weight is placed on a scale more than one time. Often expressed as a standard deviation of 5 to 10 tests. Also called reproducibility.
Reproducibility:
See Repeatability.
Resolution:
These terms are often used interchangeably to indicate how well a scale displays the correct results. Resolution is the value of the finest division of the scale. See also: Accuracy, increment, readability.RS-232A method of sending data over wires. Often used to communicate between balances and printers or computers.
Scale:
A weighing machine. The terms scale and balance are often used interchangeably. Historically a scale was a device that displayed weight by measuring a deflection, such as a spring scale. In modern weighing machines scales are usually using springs or strain gauge load cells. See also Balance.
Shift Test:
See Off Centre Loading.
Specific Gravity:
See Density Determination.
Stability:
A scale is stable when the results do not change after a weight has been added to the platform.
Stable Indicator:
A display that shows when the balance has determined the value displayed will no longer change.
Strain Gauge Load Cells:
A method to determine mass using a mechanical component that is slightly bent by the addition of an unknown mass. the amount of bending is measured by special resistors mounted on the load cell.
Tare:
To set a display to show zero weight. This is used to remove the weight of any packing or containers so that only the weight of the material within the container is shown. The Tare value is deleted from the remaining weight that can be added to a scale. For example if a scale has capacity of 500g and then 200g is tared, the remaining capacity is 300g. Often Zero is used interchangeably.
Temperature Compensation:
The ability to correct any errors introduced to the weighing system due to changes in temperature. Usually this correction is done in software on precision balances and within the load cells of less accurate scales.
Weighing:
To find the weight (mass) of an unknown against a standard known mass.
Weight:
The weight of a object is the result of gravity pulling a mass toward earth. When a balance has been calibrated using a known mass then any unknown mass placed upon the scale will have a weight proportional to the known mass. The units gram and kilogram are often used to describe the weight of on object. It is common for mass and weight to be used interchangeably. A weight can also be any mass that is used, for example to put a weight on the scale.
Zero:
To set the display to show zero weight. Used to reset the zero condition of a scale when small amounts of material are on the platform. Zero does not take away from the capacity of a scale. However it will only work in a very small range around the original zero condition for the scale. Zero and Tare are often combined on one key, the terms are often used interchangeably.