Glossary
A
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.
Application accuracy
Allowance for measuring uncertainty during practical use of a balance. Is given in the appendix to the DKD calibration certificate. |
B
Battery powered
The balance or scale is said to be battery powered when the units are operated using batteries. The battery powered units are portable and hence are often suitable for field applications.
Balances which are verified/ not approved for verification
Metrologically almost identical. For verified balances certain details are regulated by law, e.g. software changes and additional markings.
C
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.
Calibration or verification
UKAS calibration can be carried out on any balance which is in perfect working order. UKAS calibration is a private service controlled by the state for ensuring high quality requirements according to DIN EN ISO 9000ff and other standards, e. g. in production and research.
Calibration Certificate UKAS/ DaAkkS
documentation of measured characteristics of balances or test weights and of traceability to the national standard. Additional price.
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.
Conformity declaration from the manufacturer
The manufacturer declares that the product fulfils the applicable EU directives. With electronic balances this is always in conjunction with the CE mark.
Conformity evaluation
Procedure for confirming warranted characteristics in accordance with recognised rules. For balances this relates to verification.
Counting resolution
The counting resolution is calculated in points from the ratio of the weighing range
D
Data interface
To connect the balance to a printer, PC, network or a second balance. The interfaces available are stated in the model description. Typical interfaces are, for example, RS-232, USB, LAN, DUAL, Digital I/O etc. The interface parameters can be set using the balance.
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.
DMS = Strain gauge
An electrical resistor strip that is glued to an elastic deforming body made of aluminium. As the strain gauge is mechanically deformed ist resistance value changes, allowing the measured value to be calculated.
E
External Calibration
The calibration process of a balance using a known external weight often referred to as suggested calibration weight.
G
GLP
Good Laboratory Practice or GLP generally refers to a system of management controls for laboratories and research organisations to ensure the consistency and reliability of results. The laboratory balances facilitate GLP Print outs with traceability in terms of date, time, balance ID number, etc.
I
Internal Calibration
The calibration process using an internal weight available inside the balance for automatic calibration as on when desired by the user.
Internal Re-chargeable Battery
The digital balances are often powered from an internal battery which is re-charged when it is connected to the main power supply.
ISO calibration/ ISO certificate = factory calibration certificate
Testing measuring devices for accuracy in accordance with a procedure which is recognised, but not accredited.
L
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.
Load Cell
See accessories
M
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.
R
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.
Readout d
Smallest readable weight increment on a digital display
Recalibration
periodic checking of the precision of measurement equipment/ checking equipment (e.g. balances/ weights) to keep control over accuracy, → Control of measuring equipment
RS-232
A method of sending data over wires. Often used to communicate between balances and printers or computers.
S
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.
T
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.
V
Verification
According to the EU directive 2009/23/EG, balances must be verified if they are used as follows:
- in commercial trade when the price of a commodity is determined by weighing
- in the manufacture of pharmaceuticals in pharmacies and analysis in pharmaceutical and medical laboratories
- for official purposes
- in the production of prepackaging
- in medical applications
Every balance is tested by the metrological service and stamped with a verification mark. Its accuracy within the framework of permissible standard tolerances is thereby confirmed. EU verification applies to all member states of the EU.
Verification of a balance with adjusting program CAL EXT
The adjusting program is sealed with an official mark after the verification. Thus the verification is only valid fort he specific location of use
→ Gravitational force
For the preparation of verification it is therefore necessary to advise the location of use and postcode. See individual model details for the information as the whether verification can be carried out in the factory o rat the location of use.
Verification of a balance with automatic internal adjusting CAL INT
The above restrictions of the location of use do not apply, because the automatic internal adjusting works also after the verification, therefore it is not sealed. In this case the verification does not depend on the location.
Verification categories of balances
Class I – Analytical balance (precision balance)
Class II – precision balance
Class III – industrial scale (commercial scale)
Verification validity for balances
Generally 2 years for all verification categories, for control balances generally 1 year, after expiry the balance has to be reverified.
Verification value e
measure of the verification tolerance, depending on balance, mostly between 1 d and 10 d.
W
Wireless communication
for KERN balances between the platform and display device using the integrated radio module. Range within line of sight depending on the model, approx. 10 – 20 m
Weighing range [Max] is the working range of the balance. The balance can be loaded up to the specified upper limit.
Weighing unit
The balance can be set to display the weight of an unknown mass in various weighing units such as Grams, Kilograms, Milligrams, Pounds, Ounces, Carats, Grains, Newtons, etc.
Weighing with tolerance ranges
The lower and upper limiting values are programmed individually. Input is possible in grammes, pieces or %. With tolerance checks such as dosing, portion division or grading, the balance displays the value over or under the limits.