Scales
Scales are devices used for measuring weight, distinct from musical scales. They are essential across many industries including industrial, commercial, and consumer sectors.
Scales, especially industrial scales, are vital in areas such as agriculture, healthcare, laboratories, transportation, food processing, consumer goods, pharmacies, and more. They ensure accurate weight measurement for countless professional and commercial purposes.
Quick links to Scales Information
The History of Scales
Scales have been crucial since the earliest days of commerce, where items like gold were weighed to establish value. The oldest known scales, dating to 2400-1800 BC in the Indus River Valley, used a simple balance system. Merchants would balance goods against known weights to achieve equilibrium, supporting both trade and early banking.
By at least 1878 BC, Egyptians were using scales, as shown by marked stones and hieroglyphics documenting established systems for weighing precious metals such as gold.
China’s earliest scale artifact, a wooden balance with bronze weights, dates to the 3rd and 4th centuries BC. Over the centuries, various scale types appeared worldwide, but many early designs lacked accuracy, sometimes enabling dishonest practices in trade.
During the Italian Renaissance, innovators like Leonardo da Vinci and Galileo studied measurement, with Santorio Santorio creating a "weighing chair"—an early version of the modern scale—which allowed him to monitor weight changes from food and drink intake.
In the late 1600s, the drive for uniform weights led to new designs, such as the Roberval balance created in 1669 by French mathematician Gilles Personne de Roberval, which gave accurate readings regardless of where the weight was placed on the pans.
Richard Salter invented the spring scale in 1770, removing the need for counterweights and making it popular in post offices. Modern digital and electronic scales now offer much greater precision and reliability.
In 1843, Sir Charles Wheatstone improved the "Wheatstone bridge," an electrical circuit now vital to digital scale load cells. Later, the bonded strain gauge and digital scale technology further advanced weighing accuracy and efficiency.
Scale innovation continues today, such as with the "elastically deformable arm scale" introduced in 2014, which merges beam balance and spring mechanisms to weigh loads without counterweights.
Modern industrial scales deliver high accuracy, precision, and flexibility, with ongoing technological advancements driving even greater performance in the weighing industry.
Scale Design
When designing or choosing a scale, manufacturers consider factors like capacity, measurement accuracy, and portability to match the specific demands of each application. Scales can measure a wide range of weights, from milligrams to pounds, and offer portable options such as compact or mini scales. For tailored solutions, working directly with a manufacturer is recommended.
Scales may use hydraulic systems, balances, springs, load cells, or combinations of these technologies to measure weight.
Types of Scales
Scales are generally classified by their weighing method into platform and hanging scales, which represent the main categories of scale designs.
- Platform Scales
- These have a flat surface for placing items and can measure both static and moving loads. Platform scales may feature single or multiple platforms, with levers, load cells, or springs underneath for weight calculation.
- Hanging Scales
- Hanging scales measure weight by suspending the load from sensors above, ranging from large crane scales to small portable types for weighing luggage or fish.
Many specialized scales are engineered for unique functions and industries.
- Animal Scales
- Created to weigh animals accurately and comfortably, these include models for pets, livestock, and even specialty scales for specific animals like eagles.
- Balance Scales
- These use a beam and fulcrum method to determine the mass of objects.
- Bench Scales
- Bench scales are compact, durable, and used in locations such as grocery stores and pharmacies where precise weighing of small items is essential.
- Counting Scales
- Counting scales are used for counting coins, currency, or parts, featuring memory functions for inventory and manufacturing tasks.
- Crane Scales
- Crane scales measure the weight and tension of heavy lifted loads, helping prevent overloading during lifting operations.
- Digital Scales
- Digital scales offer precise readings using advanced load cell technology that converts weight into electronic signals for display.
- Electronic Scales
- Electronic scales deliver accurate measurements using motorized mechanisms and electrical signals for reliable results.
- Filling Scales
- Filling scales handle the measurement of liquids and gases, from bulk materials to precise mixtures and gas quantities.
- Floor Scales
- Floor scales are widely used in industrial environments for weighing heavy items and can accommodate carts and other transport equipment.
- Industrial Scales
- Industrial scales are designed for heavy-duty applications, providing accurate measurements for large loads crucial to trade and safety.
- Kitchen Scales
- Kitchen scales help chefs and cooks measure ingredients with precision for recipes and food preparation.
- Laboratory Scales
- Laboratory scales are highly sensitive devices used in scientific and medical labs to weigh extremely small quantities accurately.
- Mechanical Scales
- Mechanical scales operate without electricity, relying on components like springs or levers for weighing objects.
- Medical Scales
- Medical scales are essential tools in healthcare facilities for monitoring and recording patient weights.
- Portable Scales
- Portable scales are designed for convenience and easy transport, ideal for use in multiple locations.
- Retail Scales
- Retail scales allow staff and customers to measure product portions efficiently at the point of sale.
- Solar Scales
- Solar scales are powered by sunlight, converting solar energy into electricity to operate the weighing system.
- Truck Scales
- Truck scales are robust weighing platforms engineered to measure the weight of trucks and large vehicles with high accuracy.
- Wall Scales
- Wall-mounted scales offer a space-saving solution for weighing different items in a variety of settings.
Standards and Specifications for Scales
All commercial scales used in the United States must comply with National Institute of Science and Technology standards. These regulations ensure measurement accuracy for trade and protect workers across multiple industries.
Things to Consider When Purchasing Scales
When buying a scale, it’s important to choose a reputable manufacturer. Review the profiles and websites of recommended manufacturers at the top of this page. Clearly define your requirements and compare options to find a supplier who can deliver the best solution for your specific needs. The right manufacturer will focus on meeting your application’s requirements, not just offering the lowest price.
Scale Terms
- Analog Electronics
- The parts of a scale that control the weighing system within an electronic unit.
- Balance
- A device used in a scale to measure the weight of an object.
- Batching
- The act of counting, weighing, and assembling components in manufacturing processes.
- Bending-Plate System
- A weighing technique that uses metal plates to sense force and determine weight.
- Calibration
- The process of checking and adjusting a scale to ensure accurate measurements.
- Calibration Error
- The difference between a scale’s displayed weight and the object’s actual mass.
- Checkweigher
- A device that verifies the weight of products on a conveyor or production line.
- Display
- The interface that shows the weight, which can be a dial, analog, digital, or balance beam display.
- Drift
- The change in a load cell’s output signal over time or repeated use.
- Hysteresis Error
- When the same object returns different weight readings after several measurements.
- Indicator
- A component that translates a load cell’s signals into a numeric weight display.
- Instability
- A condition where the scale’s weight reading jumps or fluctuates unexpectedly.
- Junction Box
- A device that collects signals from load cells to determine an object’s weight.
- Light-Emitting Diodes (LED)
- Small semiconductors in digital scales that light up to form numbers when powered.
- Liquid Crystal Display (LCD)
- The digital readout on a scale where liquid crystals create visible weight numbers when electrically activated.
- Load
- The force or weight placed on a load cell by an item.
- Load Cell
- A sensor within a scale that transforms an item’s weight into an electronic signal.
- Load Cell System
- An arrangement of load cells used for accurate weighing.
- Load Pin
- A device that senses force to measure the weight of an object.
- Measuring Cell
- The scale component that detects weight and produces an electrical signal as output.
- Output
- The electronic signal a load cell generates when weight is applied.
- Piezoelectric System
- A weighing method using piezoelectric sensors to measure an object’s weight.
- Platform
- The flat surface on which heavy items are placed for weighing.
- Pivot
- A part that allows rotational movement in a scale mechanism.
- Reproducibility
- The ability of a scale to give the same reading for an object weighed repeatedly.
- Resolution
- The smallest increment of weight a scale can detect and display.
- Scale Pits
- Sunken areas in the ground where scales are installed.
- Strain
- The deformation that a part experiences under applied weight.
- Strain Gauge
- Transducer
- A device that changes one form of energy into another.
- Weighbridge
- A large scale with metal plates embedded in the ground, used to weigh heavy vehicles like trucks.
- Weigh-in-Motion
- Technology that uses sensors to record a vehicle’s weight as it moves over the scale, calculating total and axle-specific loads.
- Weight Module
- A device that turns an object, such as a container, into a scale by measuring its weight capacity.
- Weight
- The force of gravity acting on an object’s mass.