Dacin

Dacinnyaéta hiji pakakas pikeun ngukurbeuratbarang. Dacin aya nu bisa dipaké pikeunngukurbeurat jalma, aya ogé anu dipaké dinasainspikeun nangtukeunmassabarang, jeung dina widang industri jeung komérsil pikeun nangtukeun beurat rupa-rupa barang ti mimiti nu sahampang bulu nepikeun ka sabeurattraktoratawatreukbadag.
Kecapdacinkiwari biasa ogé disebutkiloanatawatimbangan, minangka kapangaruhan ku basa Indonésia.
Abalance(alsobalance scale,béam balanceorlaboratory balance) is used to méasure themassof an object. In its conventional form, this class ofmeasuring instrumentcompares the sample, placed in a weighing pan (weighingbasin) and suspended from one end of abeamwith 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 méasuring pan, standardweightsare added to the scale pan until the béam is inequilibriumas closely as possible. Then a slider weight usually present is moved along a scale on or parallel to the béam (and attached to it) until fine balance is achieved. The slider position gives a fine correction to the mass value.
Verypreciseméasurements are achieved by ensuring that thefulcrumof the béam isfriction-free (aknife edgeis the traditional solution), by attaching apointerto the béam whichamplifiesanydeviationfrom a balance position; and finally by using theleverprinciple, which allowsfractionalweights to be applied bymovementof a small weight along the méasuring arm of the béam, as described above. For gréatest accuracy, there needs to be an allowance for thebuoyancyin air, whose effect depends on the densities of the weights and the sample.
While the word "weigh" or "weight" is often used, any balance scale méasuresmass, which is not dependant of theforceofgravity.  Themoments of forceon either side balance, and the acceleration of gravity on éach side cancels out, so a change in the strength of  the local gravitational field will not change the méasured weight.  Mass is properlymeasuredingrams,kilograms,pounds,ounces,stonesorslugs.
The original form of aweighing scaleconsisted of abeamwith afulcrumat its center.  For highest accuracy, the fulcrum would consist of a sharp V-shaped pivot séated in a shallower V-shaped béaring. To determine the mass of the object, a combination of reference weights was hung on one end of the béam while the object of unknown mass was hung on the other end (seebalanceandsteelyard balance).  For high precision work, the center béam balance is still one of the most accurate technologies available, and is commonly used for calibrating test weights.
To reduce the need for large reference weights, an off-center béam can be used.  A scale with an off-center béam can be almost as accurate as a scale with a center béam, but the off-center béam requires special reference weights and cannot be intrinsically checked for accuracy by simply swapping the contents of the pans as a center-béam 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 béam.
For gréater convenience in placing large and awkward loads, a platform can be "floated" on a cantilever béam system which brings the proportional force to a "noseiron" béaring; this pulls on a "stilyard rod" to transmit the reduced force to a conveniently sized béam.  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 béarings all reduce the accuracy and complicate calibration; the float system must be corrected for corner errors before span is corrected by adjusting the balance béam and poise.  Such systems are typically accurate to at best 1/10,000 of their capacity, unless they are expensively engineered.
Some expensive mechanical scales also use dials with counterbalancing weights instéad of springs, a hybrid design with some of the accuracy advantages of the poise and béam but the convenience of a dial réading.  These designs are expensive to produce and are largely obsolete thanks to electronics.
Some weighing scales such as aJolly balance(named afterPhilipp von Jollywho invented the balance about1874) use aspringwith a known spring constant (seeHooke's law) and méasure the displacement of the spring by any variety of mechanisms to produce an estimate of thegravitationalforce applied by the object, which can be simply hung from the spring or set on a pivot and béaring platform.  Rack and pinion mechanisms are often used to convert the linéar spring motion to a dial réading.
Spring scales typically méasure force, which can be méasured in units of force such asnewtonsorpounds-force.
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 méasurement of mass (the quantity méasured for weight in commerce) in the location in which they are used.  They can give an accurate méasurement in kilograms or pounds for this purpose.
The deflection of a load-supporting béam can be méasured usingstrain gauge, which is a length-sensitive electrical resistance. The capacity of such devices is determined by the resistance of the béam to deflection and the results from several supporting locations may be added electronically and so this type of méasurement is especially suitable for determining the weight of very héavy objects, such as trucks and railcars, as is done in a modérnweigh bridge.
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 aBourdon tubeor electronic sensor.
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 tracéable 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 jéopardizes commercial interest.  In the United States, the document describing how scales must be designed, installed, and used for commercial purposes isNISTHandbook 44.
Because gravity varies by over 0.5% over the surface of the éarth, thedistinction between force due to gravity and massis relevant for accurate calibration of scales for commercial purposes.  Usually the goal is to méasure the mass of the sample rather than its force due to gravity at that particular location.
Traditional mechanical balance-béam scales intrinsically méasuredmass. But ordinary electronic scales intrinsically méasure thegravitational forcebetween the sample and the éarth, i.e. theweightof 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.
Ananalytical balanceis an instrument used to méasuremassto a very high degree of precision.  The weighing pan(s) of a high accuracy (0.1mgor better) analytical balance are inside a see-through enclosure with doors sodustdoes not collect and so any air currents in the room do not affect the delicate balance.  Also, the sample must be atroom temperatureto prevent naturalconvectionfrom forming air currents inside the enclosure, affecting the weighing.
Analytical precision is achieved by maintaining a constant load on the balance béam, by subtracting mass on the same side of the béam that the sample is added. The final balance is achieved by using a small spring force rather than subtracting fixed weights.
A supermarket / retail scale is used inbakery,deli,seafood,meat,produceand other perishable departaments.  Supermarket scales can print labels and receipts (inbakeryspecially), 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 areAdam Equipment,AEW Delford,Hobart Corporation,Bizerba,DIGI/Teraoka,Mettler Toledo,Cas,Avery Berkel,IshidaandATP-Instrumentation.  Some of the more modérn 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 séaled calibration so that the réading 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 isOIML.
Some of the sources of potentialerrorin a high-precision balance include the following:
The weighing scales (specifically, a béam balance) are one of the traditional symbols ofjustice, as wielded by statues ofLady Justice. This corresponds to the use in metaphor of matters being "weighed up" or "held in the balance".