 A 5 t scales, mounted on a hook of a crane A weighing scale (usually just "scale" in common usage) is a device for measuring the weight of an object. These scales are often used to measure the weight of a person, and are also used in science to obtain the mass of an object, and in many industrial and commercial applications to determine the weight of things ranging from feathers to loaded tractor-trailers. Image File history File linksMetadata No higher resolution available. ...
Image File history File linksMetadata No higher resolution available. ...
Image File history File links Metadata Size of this preview: 271 × 598 pixelsFull resolution‎ (1,376 × 3,036 pixels, file size: 1. ...
Image File history File links Metadata Size of this preview: 271 × 598 pixelsFull resolution‎ (1,376 × 3,036 pixels, file size: 1. ...
For other uses, see Weight (disambiguation). ...
Measurement is the estimation of the magnitude of some attribute of an object, such as its length or weight, relative to a unit of measurement. ...
Weight, in the context of human body weight measurements in the medical sciences and in sports is a measurement of mass, and is thus expressed in units of mass, such as kilograms (kg), or units of force such as pounds (lb). ...
A magnet levitating above a high-temperature superconductor demonstrates the Meissner effect. ...
For other uses, see Mass (disambiguation). ...
Balance A balance (also balance scale, beam balance or laboratory balance) is used to measure the mass of an object. In its conventional form, this class of measuring instrument compares the sample, placed in a weighing pan (weighing basin) and suspended from one end of a beam with a standard mass or combination of standard masses in a scale pan (scale basin) suspended from the other end. To weigh an object in the measuring pan, standard weights are added to the scale pan until the beam is in equilibrium as closely as possible. Then a slider weight usually present is moved along a scale on or parallel to the beam (and attached to it) until fine balance is achieved. The slider position gives a fine correction to the mass value. For other uses, see Mass (disambiguation). ...
Captain Nemo and Professor Aronnax contemplating measuring instruments in Twenty Thousand Leagues Under the Sea In physics and engineering, measurement is the activity of comparing physical quantities of real-world objects and events. ...
Beam may refer to: Look up beam in Wiktionary, the free dictionary. ...
For other uses, see Weight (disambiguation). ...
A standard definition of mechanical equilibrium is: A system is in mechanical equilibrium when the sum of the forces, and torque, on each particle of the system is zero. ...
Very precise measurements are achieved by ensuring that the fulcrum of the beam is friction-free (a knife edge is the traditional solution), by attaching a pointer to the beam which amplifies any deviation from a balance position; and finally by using the lever principle, which allows fractional weights to be applied by movement of a small weight along the measuring arm of the beam, as described above. For greatest accuracy, there needs to be an allowance for the buoyancy in air, whose effect depends on the densities of the weights and the sample. Image File history File links Size of this preview: 800 × 574 pixel Image in higher resolution (1932 × 1387 pixel, file size: 198 KB, MIME type: image/jpeg) Photo of a four-beam mechanical balance scale. ...
Image File history File links Size of this preview: 800 × 574 pixel Image in higher resolution (1932 × 1387 pixel, file size: 198 KB, MIME type: image/jpeg) Photo of a four-beam mechanical balance scale. ...
“Accuracy†redirects here. ...
Look up Fulcrum in Wiktionary, the free dictionary. ...
For other uses, see Friction (disambiguation). ...
It has been suggested that Software pointer be merged into this article or section. ...
For the British rock band of the same name, see Amplifier (band). ...
In radio, frequency deviation is the result of frequency modulation. ...
For the Portuguese town and parish, see Lever, Portugal. ...
For other meanings of the word fraction, see fraction (disambiguation) A cake with one quarter removed. ...
This article or section is in need of attention from an expert on the subject. ...
In physics, buoyancy is the upward force on an object produced by the surrounding fluid (i. ...
While the word "weigh" or "weight" is often used, any balance scale measures mass, which is not dependant of the force of gravity. The moments of force on either side balance, and the acceleration of gravity on each side cancels out, so a change in the strength of the local gravitational field will not change the measured weight. Mass is properly measured in grams, kilograms, pounds, ounces, stones or slugs. For other uses, see Force (disambiguation). ...
Gravity is a force of attraction that acts between bodies that have mass. ...
It has been suggested that this article or section be merged with torque. ...
Measurement is the estimation of the magnitude of some attribute of an object, such as its length or weight, relative to a unit of measurement. ...
BIC pen cap, about 1 gram. ...
Kg redirects here. ...
Officially the pound is the name for at least three different units of mass: The pound (avoirdupois). ...
The ounce (abbreviation: oz) is the name of a unit of mass in a number of different systems, including various systems of mass that form part of English units, Imperial units, and United States customary units. ...
The stone is a unit of mass in the Imperial system of weights and measures used in the United Kingdom, Ireland, and most Commonwealth countries. ...
The slug is an English unit of mass. ...
 Public mass balance for weighing people The original form of a weighing scale consisted of a beam with a fulcrum at its center. For highest accuracy, the fulcrum would consist of a sharp V-shaped pivot seated in a shallower V-shaped bearing. To determine the mass of the object, a combination of reference weights was hung on one end of the beam while the object of unknown mass was hung on the other end (see balance and steelyard balance). For high precision work, the center beam balance is still one of the most accurate technologies available, and is commonly used for calibrating test weights. Image File history File linksMetadata Download high-resolution version (2616x3488, 3994 KB) Cismigiu Park public weight measure. ...
Image File history File linksMetadata Download high-resolution version (2616x3488, 3994 KB) Cismigiu Park public weight measure. ...
Beam may refer to: Look up beam in Wiktionary, the free dictionary. ...
Look up Fulcrum in Wiktionary, the free dictionary. ...
For meanings of the word balance, see: Look up balance in Wiktionary, the free dictionary. ...
A steelyard balance is a straight-beam balance with arms of unequal length. ...
To reduce the need for large reference weights, an off-center beam can be used. A scale with an off-center beam can be almost as accurate as a scale with a center beam, but the off-center beam requires special reference weights and cannot be intrinsically checked for accuracy by simply swapping the contents of the pans as a center-beam balance can. To reduce the need for small graduated reference weights, a sliding weight called a poise can be installed so that it can be positioned along a calibrated scale. A poise adds further intricacies to the calibration procedure, since the exact mass of the poise must be adjusted to the exact lever ratio of the beam.
For greater convenience in placing large and awkward loads, a platform can be "floated" on a cantilever beam system which brings the proportional force to a "noseiron" bearing; this pulls on a "stilyard rod" to transmit the reduced force to a conveniently sized beam. One still sees this design in "portable beam scales" of 1000 lb or 500 kg capacity which are commonly used in harsh environments where electricity is not available, as well as in the lighter duty mechanical bathroom scale. The additional pivots and bearings all reduce the accuracy and complicate calibration; the float system must be corrected for corner errors before span is corrected by adjusting the balance beam and poise. Such systems are typically accurate to at best 1/10,000 of their capacity, unless they are expensively engineered. Image File history File linksMetadata No higher resolution available. ...
Image File history File linksMetadata No higher resolution available. ...
Some expensive mechanical scales also use dials with counterbalancing weights instead of springs, a hybrid design with some of the accuracy advantages of the poise and beam but the convenience of a dial reading. These designs are expensive to produce and are largely obsolete thanks to electronics.
Spring scale
 A spring weighing scale can measure forces transmitted through the scale in any direction. -
Main article: Spring scale Some weighing scales such as a Jolly balance (named after Philipp von Jolly who invented the balance about 1874) use a spring with a known spring constant (see Hooke's law) and measure the displacement of the spring by any variety of mechanisms to produce an estimate of the gravitational force applied by the object, which can be simply hung from the spring or set on a pivot and bearing platform. Rack and pinion mechanisms are often used to convert the linear spring motion to a dial reading. Download high resolution version (390x708, 61 KB)This weighing scale measures the weight of an object using an internal spring and its known spring constant. ...
Download high resolution version (390x708, 61 KB)This weighing scale measures the weight of an object using an internal spring and its known spring constant. ...
Spring scale. ...
Johann Philipp Gustav von Jolly (* September 26, 1809 in Mannheim, †December 24, 1884 in Munich) was a German physicist and mathematician. ...
Year 1874 (MDCCCLXXIV) was a common year starting on Thursday (link with display the full calendar) of the Gregorian calendar (or a common year starting on Saturday of the 12-day slower Julian calendar). ...
For other uses, see Spring. ...
Hookes law accurately models the physical properties of common mechanical springs for small changes in length. ...
Gravity is a force of attraction that acts between bodies that have mass. ...
Spring scales typically measure force, which can be measured in units of force such as newtons or pounds-force. For other uses, see Newton (disambiguation). ...
The pound-force is a non-SI unit of force or weight (properly abbreviated lbf or lbf). The pound-force is equal to a mass of one pound multiplied by the standard acceleration due to gravity on Earth (which is defined as exactly 9. ...
Spring scales typically cannot be used for commercial applications unless their springs are temperature compensated or used at a fairly constant temperature. The spring scales which are legal for commerce can be calibrated for the accurate measurement of mass (the quantity measured for weight in commerce) in the location in which they are used. They can give an accurate measurement in kilograms or pounds for this purpose.
Strain gauge scale The deflection of a load-supporting beam can be measured using strain gauge, which is a length-sensitive electrical resistance. The capacity of such devices is determined by the resistance of the beam to deflection and the results from several supporting locations may be added electronically and so this type of measurement is especially suitable for determining the weight of very heavy objects, such as trucks and railcars, as is done in a modern weigh bridge. Typical foil strain gauge. ...
A weigh bridge at a gravel pit. ...
Hydraulic or pneumatic scale It is also common in high-capacity applications such as crane scales to use hydraulic force to sense weight. The test force is applied to a piston or diaphragm and transmitted through hydraulic lines to a dial indicator based on a Bourdon tube or electronic sensor. Many techniques have been developed for the measurement of reduced or increased pressures. ...
Testing and certification Most countries regulate the design and servicing of scales used for commerce. This has tended to cause scale technology to lag behind other technologies because expensive regulatory hurdles are involved in introducing new designs. Nevertheless, there has been a recent trend to "digital load cells" which are actually strain-gage cells with dedicated analog converters and networking built into the cell itself. Such designs have reduced the service problems inherent with combining and transmitting a number of 20 millivolt signals in hostile environments.
Government regulation generally requires periodic inspections by licensed technicians using weights whose calibration is traceable to an approved laboratory. Scales intended for casual use such as bathroom or diet scales may be produced, but must by law be labelled "Not Legal for Trade" to ensure that they are not repurposed in a way that jeopardizes commercial interest. In the United States, the document describing how scales must be designed, installed, and used for commercial purposes is NIST Handbook 44. NIST logo The National Institute of Standards and Technology (NIST, formerly known as The National Bureau of Standards) is a non-regulatory agency of the United States Department of Commerce’s Technology Administration. ...
Because gravity varies by over 0.5% over the surface of the earth, the distinction between force due to gravity and mass is relevant for accurate calibration of scales for commercial purposes. Usually the goal is to measure the mass of the sample rather than its force due to gravity at that particular location. For other uses, see Weight (disambiguation). ...
Traditional mechanical balance-beam scales intrinsically measured mass. But ordinary electronic scales intrinsically measure the gravitational force between the sample and the earth, i.e. the weight of the sample, which varies with location. So such a scale has to be re-calibrated after installation, for that specific location, in order to obtain an accurate indication of mass. For other uses, see Mass (disambiguation). ...
This article covers the physics of gravitation. ...
For other uses, see Weight (disambiguation). ...
Analytical balance
 Mettler digital analytical balance with 0.1 mg precision. An analytical balance is an instrument used to measure mass to a very high degree of precision. The weighing pan(s) of a high accuracy (0.1 mg or better) analytical balance are inside a see-through enclosure with doors so dust does not collect and so any air currents in the room do not affect the delicate balance. Also, the sample must be at room temperature to prevent natural convection from forming air currents inside the enclosure, affecting the weighing. Image File history File links Download high-resolution version (1200x1600, 92 KB) File links The following pages on the English Wikipedia link to this file (pages on other projects are not listed): Weighing scale Mettler Toledo User:Itub ...
Image File history File links Download high-resolution version (1200x1600, 92 KB) File links The following pages on the English Wikipedia link to this file (pages on other projects are not listed): Weighing scale Mettler Toledo User:Itub ...
For other uses, see Mass (disambiguation). ...
The milligram (symbol mg) is an SI unit of mass. ...
Look up dust in Wiktionary, the free dictionary. ...
For other uses, see Room temperature (disambiguation). ...
Convection in the most general terms refers to the movement of currents within fluids (i. ...
Analytical precision is achieved by maintaining a constant load on the balance beam, by subtracting mass on the same side of the beam that the sample is added. The final balance is achieved by using a small spring force rather than subtracting fixed weights.
Supermarket / Retail scale A supermarket / retail scale is used in bakery, deli, seafood, meat, produce and other perishable departaments. Supermarket scales can print labels and receipts (in bakery specially), marks Weight/Count, Unit Price, Total Price and in some cases Tare, a supermarket label prints weight/count, unit price and total price. Some manufacturers are Adam Equipment, AEW Delford, Hobart Corporation, Bizerba, DIGI/Teraoka, Mettler Toledo, Cas, Avery Berkel ,Ishidaand ATP-Instrumentation. Some of the more modern Supermarket scales will print a RFD tag which can be used to track the item for tampering or returns. In most cases these type of scales have a sealed calibration so that the reading on the display is correct and cannot be tampered with - in the USA the approval is NTEP, for South Africa it is SABS, the UK it is OIML. Bakery foods A baker is someone who bakes and sells bread, cakes and similar foods. ...
The word delicatessen designates a kind of food store. ...
Spaghetti with seafood (Spaghetti allo scoglio). ...
This article is about the food. ...
Produce on display at La Boqueria market in Barcelona, Spain. ...
Bakery foods A baker is someone who bakes and sells bread, cakes and similar foods. ...
Hobart is a manufacturer of equipment used in food service operations. ...
Logo Bizerba GmbH & Co. ...
METTLER TOLEDO is a manufacturer producing weighing instrument and analytical instruments. ...
Cas may be Calcium sulfide, the chemical compound with the formula CaS Cas (people), an ancient people Cassiopeia (constellation), standard astronomical abbreviation Cas, an acid tasting type of guava that grows in Costa Rica, psidium friedrichsthalium. ...
Avery Berkel, a major manufacturer of weighing systems and food processing equipment, was formed in 1993 when the British conglomerate GEC combined their GEC Avery Ltd business with the newly acquired Berkel company. ...
Inspector Ishida in the center on the job and about to face an occupational hazard Inspector Ishida is a popular supporting character in the Usagi Yojimbo comic book series. ...
The International Organization of Legal Metrology (OIML, Organisation Internationale de Métrologie Légale) is an intergovernmental treaty organization whose membership includes Member States (59), countries which participate actively in technical activities, and Corresponding Members (55), countries which join the OIML as observers. ...
Sources of error Some of the sources of potential error in a high-precision balance include the following: In statistics and optimization, the concepts of error and residual are easily confused with each other. ...
- Buoyancy, due to the fact that the object being weighed displaces a certain amount of air, which must be accounted for. High-precision balances are often operated in a vacuum.
- Error in reference weight (used to cheat in measurement)
- Air gusts, even small ones, may push the scale up or down.
- Friction in the moving components may prevent the scale from reaching equilibrium.
- Settling airborne dust may contribute to the weight.
- Scale may be uncalibrated or mis-calibrated. The calibration of any electronic circuits may drift over time, or due to temperature changes.
- Mechanical components may be mis-aligned.
- fulcrum of the balance locking square-square lock instead of free movement circle/point (used to cheat in measurement)
- Shortening the arm by putting chain for the pan over the beam (used to cheat in measurement).
- Mechanical misalignment due to thermal expansion/contraction of components of the balance.
- Earth's magnetic field may act on iron components in the balance.
- Magnetic fields from nearby electrical wiring may act on iron components.
- Placing a weak magnet under the object to be measured (used to cheat in measurement)
- Magnetic disturbances to electronic pick-up coils or other sensors.
- Forces from electrostatic fields, for example, from feet shuffled on carpets on a dry day.
- Chemical reactivity between air and the substance being weighed (or the balance itself, in the form of corrosion).
- Condensation of atmospheric water on cold items.
- Evaporation of water from wet items.
- Convection of air from hot or cold items.
- The Coriolis force from Earth's rotation.
- Gravitational anomalies (i.e. using the balance near a mountain; failing to level and recalibrate the balance after moving it from one geographical location to another.)
- Vibration and seismic disturbances; for example, the rumbling from a passing truck.
- Scales placed on soft surface, Carpet or rubber mat. (You can try this one at home)
In physics, buoyancy is the upward force on an object produced by the surrounding fluid (i. ...
For other uses, see Friction (disambiguation). ...
Look up Fulcrum in Wiktionary, the free dictionary. ...
In physics, thermal expansion is the tendency of matter to change in volume in response to a change in temperature. ...
Magnetic field lines shown by iron filings Magnetostatics Electrodynamics Electrical Network Tensors in Relativity This box: In physics, the magnetic field is a field that permeates space and which exerts a magnetic force on moving electric charges and magnetic dipoles. ...
In physics, an electric field or E-field is an effect produced by an electric charge that exerts a force on charged objects in its vicinity. ...
For the hazard, see corrosive. ...
For other uses, see Condensation (disambiguation). ...
“Vaporization†redirects here. ...
Convection in the most general terms refers to the movement of currents within fluids (i. ...
In physics, the Coriolis effect is an inertial force first described by Gaspard-Gustave Coriolis, a French scientist, in 1835. ...
Symbolism The weighing scales (specifically, a beam balance) are one of the traditional symbols of justice, as wielded by statues of Lady Justice. This corresponds to the use in metaphor of matters being "weighed up" or "held in the balance". Image File history File links Unbalanced_scales. ...
Image File history File links Unbalanced_scales. ...
This article is about the concept of justice. ...
Lady Justice Lady Justice (Iustitia, the Roman Goddess of Justice and sometimes, simply Justice) is an allegorical personification of the moral force that underlies the legal system. ...
See also An objects weight, henceforth called actual weight, is the downward force exerted upon it by the earths gravity. ...
Nutrition scales are generally weighing instruments that output precise nutritional information for foods or liquids placed upon them. ...
This sketch shows a Roberval balance with balanced masses. ...
A steelyard balance is a straight-beam balance with arms of unequal length. ...
A weigh lock is a specialized canal lock designed to determine the weight of barges in order to asses toll payments based upon the weight and value of the cargo carried. ...
Griffith Elder weighbridge in operation. ...
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