This article contains everything you need to know about Platform Industrial Scales.
Read further and learn more about:
A platform scale is a scale that measures the weight of objects loaded on a flat platform. The function of the platform is to transmit the weight of the object to the internal measuring device and to support the object during weighing. Several types of devices can be installed within the platform scale to aid in the calculation of weight. There is a wide range of platform scale designs, sizes, and load capacities available depending on the needs of the customer or the user.
Platform scales are practically used everywhere. They are widely used in trading, manufacturing, logistics, and service industries to measure or verify the weight of material. In those number-driven industries, having the correct weight measurement matters when it comes to generating revenues, maintaining safety, and upholding the quality of services and products. The application of platform scales is not limited to commercial and industrial purposes; these scales are also capable of making small-scale weight measurements for personal, domestic, medical, and laboratory applications.
The operation of platform scales is straightforward for the user. The object to be weighed is placed on the platform, and the rest of the work is performed by the platform scale. The object applies compressive force to the platform; this force is transmitted to the mechanism inside the platform scale that is responsible for converting it into a weight measurement the user can read and record. The process ends by displaying the reading on the screen or indicator of the platform scale.
The two main classifications of platform scales are electronic and mechanical platform scales. They differ on the mechanism used for determining the weight of an object. The latter is a type of platform scale that relies on levers, springs, and reference weights in obtaining the weight measurement.
Load cells are transducers that convert mechanical force and weight into measurable electrical output. They are abundantly used in most electronic scales. Some of the commonly used load cells in weighing equipment are as follows:
In strain gauge load cells, strain gauge assemblies are contained inside the load cell housing. A strain gauge is an electronic sensor containing a metal foil insulated by a flexible substrate that changes its resistance as a response to an applied external force. A voltage fluctuation is encountered from the deformation of the metal foil as electrical current passes through the leads of the strain gauge. The change in voltage is converted by a digital meter into weight.
The types of strain gauge load cells commonly used in platform scales include single point, planar beam, bending beam, shear beam, dual shear beam, and S-type load cells.
Hydraulic load cells consist of a piston, an elastic diaphragm, and a cylindrical chamber filled with fluid. These components are welded together inside the load cell housing and are pressure-tested to ensure no fluid leakage will be encountered. When a compressive force is applied on the top of the piston, it causes the piston to compress the fluid inside the chamber. The internal pressure of the fluid rises, and the weight of the object is calculated from the change of internal pressure of the fluid.
Since there are no electrical components, hydraulic load cells remain stable from lightning damage and electrical surges. They are ignition-proof devices that can be operated in hazardous areas prone to explosions. They provide reliable service when weighing chemicals, fuels, and flammable materials. Applications of hydraulic load cells can include bin, tank, and hopper weighing.
Scales differ from balances. Scales measure the weight of the objects, while balances measure mass. The measurement obtained from balances remains unaffected by the local acceleration due to gravity.
Floor scales are platform scales that are designed to lie on the floor surface. They are usually seen in factories, warehouses, and shipping companies. They are constructed and designed to carry heavier loads and withstand harsh and hazardous conditions that may arise from these environments. There are several kinds of floor scales, each with different capabilities and features for a customer to choose from:
A basic floor scale is the simplest type of floor scale. Items are placed on top of its rectangular platform, which simply sits on the floor. The top of the platform is inclined from the floor. The items are placed on the top of the floor scale either manually or by moving equipment (e.g., pallet jack, forklift, pushcart, hand-truck). There are two options in facilitating the mounting of items onto a basic floor scale:
Ramps may be installed on the edges of the floor scale to effectively load and unload the items to be weighed. However, the ramp takes up additional floor space, especially if multiple edges must be accessed. It can also be risky for the worker to push a heavy load onto the floor scale.
Placing the floor scale in a pit frame is another option for basic floor scales to eliminate the hazard to the worker and minimize floor space. Pit frames may be installed slightly below the floor to level the platform of the floor scale with the surface of the floor. However, the installation creates additional costs.
The succeeding types are modifications of the basic floor scale.
A low profile floor scale is a type of floor scale that is similar to the basic floor scale, but its platform is much closer to the ground. The inclination of the platform top ranges from 1 – 2 inches above the ground. This makes manual loading and unloading easier for the worker, and it becomes more accessible to the moving equipment. A hinged ramp may be installed on the edge of the scale to facilitate the loading and unloading of items.
Low profile floor scales may have raised side rails with load cells underneath them to accurately weigh large items. However, this design can be an issue for oddly-shaped items.
Washdown scales (or lift scales) are a type of floor scale that has a liftable top deck to allow access to its interior components for thorough cleaning and maintenance. The top deck may be lifted manually or automatically by using a pneumatic or hydraulic system. The electronic components are protected during washing and exposure from the harsh substances during their operation.
Washdown scales are used for weighing liquids and corrosive chemicals and for applications that require high levels of sanitation such as food, beverage, agricultural, and pharmaceutical products. Those applications require frequent cleaning to keep the scale in top condition and to avoid chemical and microbial contamination. Washdown scales are made from materials that have high chemical and corrosion resistance, such as stainless steel, to withstand these applications.
Portable floor scales have increased mobility when compared to other floor scale types. Having a portable floor scale is oftentimes more economical than setting up multiple floor scales in the vicinity where it is installed.
To gain from their mobility advantage, most portable floor scales are battery-powered with a rechargeable feature to readily operate them at multiple locations without depending on a stationary electrical outlet. They have durable caster or rubber wheels at the bottom of their platform to move the portable floor scale by sliding. These features allow you to weigh objects anywhere in an industrial setting. A ramp may also be installed for added convenience.
In pallet scales (or U-scales), the pallet jack and other handling equipment load the palletized goods at the center of the U-shaped floor scale for weighing. This eliminates the need for the installation of a ramp and increases space efficiency because maneuvering at the edge of the scale during loading and unloading is not necessary for the handling equipment.
Flexure lever scales are heavy-duty scales that can endure high stress and impact force from sudden movement during loading.
Bench scales are platform scales that are designed to fit on tabletops, counters, and workstations. They have a compact design and consume less space than floor scales. The object to be weighed is placed on the pan of the bench scale; the pan can be removed for easy cleaning. The weight capacity that a bench scale can measure is lower than floor scales. Bench scales are less suitable for weighing oversized objects.
Bench scales serve a variety of commercial and industrial functions. To expand their functionality, bench scales are programmed and automated to increase production, service quality, and efficiency. A computing system is used to readily make calculations of other information based on the weight of the goods. The special types of bench scales, which perform functions aside from basic weighing, are the following:
A checkweigher is a type of bench scale used to verify if the weight of packaged products and materials are within specification limits. It recognizes if the products weighed are within acceptable weight, overfilled, or underfilled. Indicators such as audible alarms and color-coded lights are incorporated in the checkweigher as a product weight pass-or-fail gauge. In the shipping and transportation industry, a version of a checkweigher can be found; it verifies if the weight of luggage and goods are within allowance.
Checkweighers may be dynamic or static. Dynamic or in-motion checkweighers are installed in a conveying system of a production or scanning line that accurately weighs all products carried by the conveyor. This results in an increased throughput rate and efficiency. Static checkweighers, on the other hand, rely on manual loading and unloading to initiate weighing
Counting scales allow weighing and counting of the number of items in bundled or packaged goods that contain identical items. Before the operation, the theoretical or assigned weight of an individual item is determined and stored in the memory of the counting scale. The bundled goods are precisely weighed, then the computing system of the counting scale calculates the exact count based on the measured weight obtained and the weight of an individual item set at the beginning of the operation. A single counting scale is capable of weighing different kinds of items depending on the memory of the computing system.
Counting scales save time and effort from manual counting of numerous items. They are useful in goods inspection of incoming and outgoing materials in production facilities and shipping industries. Tracking the inventory of items is made easier by bench counting scales in warehouses, stores, and other facilities.
Mixing scales are used in the accurate weighing of very fine ingredients in production processes that result in a large impact on the quality and characteristics of a product. They are commonly used in manufacturing automotive paint.
Laboratory scales are used in weighing chemical and biological samples to be used for analytical procedures, scientific experiments, and quality control procedures performed in the laboratory. These scales possess high accuracy, precision, and readability to lessen calculation errors that can interfere with the reproducibility of results. Tarring is allowed in laboratory scales; this is the act of bringing the weight of a particular object (usually the container) to zero, so it is not included in the final weight once the contents are poured.
Truck scales are used for weighing vehicles and their carried load for the tracking of overloaded vehicles on highways and bridges and for monitoring incoming and outgoing volumes in various facilities. Truck scales are similar to large floor scales with a very high load capacity; they are situated in highway checkpoints and inspection stations. Since truck scales measure large volumes, they require more load cells. A typical truck scale requires 6-12 load cells.
The platform where the vehicles are supported is called a weighbridge. The construction of a weighbridge is highly customizable; customers may choose between using a pitted or pitless installation. Pitless weighbridges are inclined above the ground; this necessitates at least two ramps on its opposite edges that serves as the path for loading and unloading of the vehicles. On the other hand, pitted weighbridges are built on an excavation to level its topmost surface with the ground; this eliminates the need for ramps and saves space.
Furthermore, the material of construction of the weighbridge can be concrete or steel. Steel weighbridges have lighter weight and can be easily installed. Concrete weighbridges have a heavier weight and take time to settle due to the curing of concrete but are more rigid and do not allow loads to slip when wet. Both materials perform well in harsh outdoor environments and can withstand heavy and continuous loads.
Forklift scales increase efficiency by having a weighing element installed that automatically measures and records the weight of bundled loads such as palletized goods and drums as soon as they are placed on the forks of the forklift truck. The weighing component of forklift scales takes only a few minutes to be installed on a forklift, and it can be easily dismantled for scheduled maintenance and servicing. Using forklift scales saves time otherwise used traveling back and forth to a fixed scale and reduces the chances of gradual wear and tear of the forklift engine from such activities.
Pallet jack scales are specialized pallet jacks that weigh a load once it is carried. They also help in augmenting operational efficiency.
The previous chapter listed the different types of platform scales that offer diverse features depending on the customer‘s needs and desired level of service and automation. The following aspects need to be examined when choosing, upgrading, and maintaining a platform scale:
Capacity is the heaviest load the platform scale can measure. This is one of the most important specifications to look for in platform scales. However, platform scales with higher capacities are not always the best option, as increasing capacity generally reduces accuracy. Investing in and maintaining higher capacity platform scales is also more expensive. Therefore, you should select a capacity only reasonably higher than the estimated heaviest load to be weighed.
Readability refers to the smallest division at which the scale or balance can be read. It designates the number of decimal places on the measurement value to be produced by the platform scale. Higher readability means higher accuracy and a greater number of significant figures of the measurements produced by the scale. This aspect is critical for laboratory scales in reducing calculation errors and for weighing valuable items in which every milligram matters. Also, smaller increments mean higher functionality of weighing sensors used in the scale.
Accuracy is the closeness of the measurement obtained from the platform scale to the true measurement value. The accuracy of platform scales is monitored and preserved by periodic calibration.
Linearity is the property of a scale that refers to its capability of obtaining the correct weight from zero weight to its full capacity. It is measured experimentally by obtaining the measurements of objects with known weights. When the data is plotted, it should generate a straight line. Another way to test linearity is to cut a stable sample into exact halves and weigh the individual halves separately. The sum of the weights obtained must be equal to the measurement if they are weighed together.
Drift refers to fluctuation while weighing a sample, causing the readings to erratically change. This instability causes inconsistent and inaccurate measurement. Drift is attributed to environmental factors such as temperature inconsistency, vibration, air currents, static electricity, and radio frequency interference (RFI). It can be eliminated by the installation of ionizers and by placing the platform scale in an area with no RFI, vibration, or air current.
The materials of construction must be considered when choosing a platform scale. Platform scales must be made with rigid and tough materials, such as steel (e.g., carbon steel, stainless steel) and aluminum (for smaller capacities) in order to support the load during weighing. Corrosion resistance is another factor and is enhanced by the application of a coating. Rugged platform surfaces may also be chosen to prevent the slipping of loads during placement.
When choosing a platform scale, consider the volume of the items to be weighed and the floor space available where it will be situated. Voluminous items are suited to be weighed on a floor scale, while smaller items can be accommodated on a bench scale. Also, check the inclination of the platform scale and assess if a ramp or a pit frame is necessary. It will be challenging to place heavier loads on the platform if the inclination is too high.
When the platform scale is exposed to harsh and wet environments (i.e., prone to spills), and it could be a cause of cross-contamination, cleaning must be done regularly and frequently. There are types of platform scales that are flexible enough, such as washdown scales, to accommodate and ease regular cleaning and sanitation.
Automated systems, such as automated weight verification and data transmission and collection systems, may be integrated into platform scales to increase the efficiency and accuracy of operations. However, more automatic features require higher investment costs.
A load cell is a transducer which converts mechanical energy (tensile and compressive forces) into electrical signals. There are different transducer operating principles that can be utilized to convert forces...
A strain gauge, or strain gage, is a sensing device used for measuring strain experienced by an object. It is made from a long, thin piece of conductor bonded to an elastic backing material called a carrier...
A load pin is a sensor utilized to measure force or weight in various research, control, measurement and testing applications. The load pin force sensor converts a force into an electrical signal. The load pins provide durable and...
At the heart of every weighing device is a sensor called a load cell. When an item is put on a load cell, it senses the force of the gravitational pull of the weight, which an electronic circuit processes to display as data...