A scale is a device that measures the amount of weight an object or a person has. It can either be digital or mechanical and comes in different sizes to accommodate different objects.
The proliferation of definitions of scaling has created conceptual ambiguity. A critical question is what constitutes a rigorous approach to scale development.
Weight Measurement
Weighing is a necessary tool for many industries, from manufacturing medications to building airplanes. Knowing the amount of matter contained in an object or person allows us to accurately calculate how much the item will weigh, how much it will cost and how difficult it will be to transport, carry or move.
While scales come in a variety of forms, they all measure weight by utilizing mechanical components or electrical sensors. Almost all modern electronic scales work through load cells, which record the weight of an object by measuring its force, and then converting that information into digital readouts on a display.
Because these components can change over time, scales should be stored in a stable environment, away from vibration or temperature changes. Temperature changes can cause load cells to expand or contract, which can affect accuracy. Vibration from nearby machinery or powerful air conditioning can also be misinterpreted by a load cell as weight, and therefore affect the scale’s reading.
Force Measurement
The measurement of force is an important part of testing products, materials, components and assemblies. Engineers, manufacturers and test labs use tensile tests, compression tests and shear tests to assess the strength of products and to ensure quality in production.
A scale measures force by reporting the change in spring displacement that occurs when the weight of an object is hung from it, opposing the force of gravity. The scale’s display indicates the measured force in units like newtons.
Digital force gauges or load cells convert the physical intensity of a measured force into an electronic signal. They typically include a strain gauge sensor that deforms under a load, signal conditioning to improve the signal-to-noise ratio and an acquisition system that monitors and records acquired data. They can also be integrated with a computer and software for real-time monitoring, recording and analysis. A variety of options are available, such as measuring units, display type, sampling rate and more.
Accuracy
The accuracy of a scale refers to how close the instrument comes to displaying a correct weight value. This measurement is separate from precision, which is the degree to which repeated measurements under unchanged conditions show consistent results.
A scale’s accuracy can be improved by keeping it clean, storing it in a stable environment and avoiding overloading it. It’s also important to calibrate it regularly and handle it carefully to avoid damage to its sensitive load cells.
Accuracy, along with resolution and repeatability, are the four main specifications that determine a scale or balance’s performance. It’s important to remember that, even with accurate calibration, a defective load cell can produce inaccurate weight readings. This is why it’s important to use calibration weights that are known for their accuracy. This way, if the calibration is off, it’s easily identified. If this is the case, it must be repaired or replaced to restore the scale’s accuracy. This can only be done by a qualified service technician.
Electronics
Digital scales use electronic circuitry to measure and display weight on a LCD screen. Unlike mechanical balances that use physical principles and components to determine the force of an object (weight), electronic devices convert analog input data into discrete digital information similar to the way CD and MP3 encoding schemes digitize audio waveforms.
These devices may have a variety of additional features such as multi-unit support, scan function and data transfer capabilities. They also come in various capacities and sensitivity levels, which are important considerations for customers.
A good electronic scale is sturdy, stable and able to adapt to different gravity conditions. It should have a large, clear and easily readable display. Moreover, it must be handled gently because the internal sensors and microcontroller are sensitive to even slight reverberations. This is why it is necessary to follow the product instructions for calibration and maintenance.