| Accuracy: |
These
terms are often used interchangeably to indicate how well
a scale displays the correct results. Accuracy is 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. |
| Check Weighing: |
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. |
| 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. |
| 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. |
| Minimum Capacity: |
The minimum weight that the scale
or balance can accurately measure within the tolerances
specified. |
| 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. |
| 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. Sometimes referred to as the smallest readable
weight value |
| Resolution: |
Resolution is the value of the finest
division of the scale. Sometimes referred to as the smallest
reading possible. |
| 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. |
| RS-232: |
A 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. |
| 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.
|