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Scale Theory

collaborating weighing scale

By June 3, 2024 0 Comments
Calibrating weighing scales/instruments
1. Preparations before calibration:
Before you can start the calibration of the weighing instrument, you should clarify a few things and get prepared. You should find out the technical characteristics of the weighing instrument (max weight, d value), the accuracy requirement (max error allowed and uncertainty) and what to do if the calibration fails (adjustment). Typically, the whole measurement range is calibrated and the calibration is performed in the location where the instrument is being used. Make sure you have enough weights for the calibration procedure available. The weighing instrument should be switched on atleast 30 minutes before the calibration. The temperature of the weights should be stabilized to the same temperature where the calibration is to be done. The weighing instrument should be at a horizontal level, especially for small and accurate weighing instruments. Perform a few pre-tests by placing weights close to the maximum of the range on the instrument and to ensure it works normally. In case the weighing instrument fails in calibration and it is adjusted, you should make an “as found” calibration before adjustment and an “as left” calibration after adjustment.
2. Eccentricity Test:
In normal use of a weighing instrument, the load is not always placed perfectly on the center of the load receptor. Sometimes the results of a weighing instrument can vary slightly depending on if the load is placed in different locations on the load receptor. In order to test how much effect the location of the load has, the eccentricity test is performed. In the eccentricity d bd test, the reference load is placed in a few different specified locations on the load receptor. First, the load is placed in the center of the load receptor (the load’s center of gravity) and the result is observed. Next, the load is placed in four different sectors of the load receptor, as illustrated in the picture which is for rectangular and round load receptors, but naturally, in practice, there are many different shapes of load receptors and the location of the load will vary. Standards OIML R76 and EN 45501 will give guidance for different load receptor shapes. The calibration procedure should specify where to place the load during the test and calibration results (in certificate format) should also document the locations. The test load used in an eccentricity test should be atleast one-third (1/3) of the max load of the weighing instrument. The test should preferably be done using just one test load, if possible. That way it is easier to be sure that the load’s center of gravity is in the specified location. For a weighing instrument with multiple ranges, the eccentricity test should be done with the highest range. As the aim of the eccentricity test is to find out the difference caused by the location of the load, it is not necessary to have an accurate calibrated load. It is naturally important to use the same load throughout the test. If the eccentricity test is used also to determine the errors of the indication, then a calibrated load should be used.
3. Procedure for the Eccentricity Test:
The indication is zeroed before the test. The test load is placed to location 1 and indication is recorded. The test load is then moved to locations 2 to 5 and indication is recorded in each location. Finally, the test load is placed again to location 1 to check that the indication has not drifted from the earlier indication in location
1. The zero may be checked between each location to see that it has not changed. If necessary, the instrument can be zeroed in between each test.
Alternatively, you may also tare the instrument when the load is in location number 1, as this makes it easier to see any difference between locations
Scale Theory

customized weighing system

By June 3, 2024 0 Comments
Weighing systems have advanced significantly throughout the years, but there are new developments that provide companies with smarter solutions that are not only speeding up specific tasks, but also minimizing inaccuracies.
Customized weighing systems: Competition is driving many Customized Weighing Systems companies to increase production and profits. One of the many ways to increase the bottom line is by improving the weighing technologies used in various stages of the manufacturing, packing and distribution process. Customers today looking to buy industrial scales no longer depend on off the shelf options because many suppliers are willing to accommodate customized requests. Clients can have weighing scales made according to their needs with features such as data sorting and analysis, remote function and trade compliance. Although custom weighing scales are generally more expensive, increasing efficiency in the production and distribution process will pay off over time. Remote access and monitoring: Innovation in connectivity leads to the development of weighing scales used in a variety of innovative applications. For example, a weighing scale may be used to monitor inventory in warehouses or check the health of animals in holding paddocks. Nowadays, digitally- enabled weighing scales are also capable of transmitting data into mobile devices or computers even when used in a remote location. In the agriculture industry, remote monitoring using digital weighing scales has made it more convenient for farmers to manage the health of livestock. Data received from weighing scales in the stockyard can help in deciding the necessary treatments or amount of feed to give to animals to ensure that they are in optimum health.
Apart from livestock monitoring, a remote capability is a helpful feature to have when you are checking the inventory levels in warehouses, retail outlets and processing lines. Weighing scales can be installed in shelves and containers to determine when the weighing changes and there is a need to replenish supplies. Using Livestock scales to measure animal performance Integration of Weighing Technology: Weighing technology has evolved from a simple application to a process that is incorporated into the supply chain. Eventually, weighing scales will also play a vital role in reducing human intervention in the production process along with advancements in IoT.

Some of the innovative applications of Weighing technology include:
*Quality control: By integrating weighing technology in various stages of production, it is more convenient to check for supply fluctuations in real-time.
POS Weighing Scale Integration *Data collection and logging:
Collecting data using digital weighing scales automatically move the information into databases with accompanying software that will analyze and evaluate the data to come up with actionable solutions.
Scale Theory

Ensuring Fair Trade and Consumer Protection

By June 3, 2024 0 Comments
Ensuring Fair Trade and Consumer Protection:
Metrology is significant in trade and commerce as the guardian of fair transactions and consumer protection. It helps to ensure that measuring instruments utilized in commercial transactions are producing accurate readings. Not only does this prevent customers from being overcharged, but it also protects sellers from giving away more of a product than was purchased. Metrology is crucial in trade and commerce. It is a fundamental pillar of protection that provides transparency & validity to transactions. In many countries, regulatory bodies enforce laws that dictate the method used to and the frequency at which, measurement equipment must be calibrated to be used in commerce. These regulations apply to weighing scales, fuel pumps, electricity meters and other measuring instruments used in commercial transactions. These regulations require a licensed service provider to calibrate the measurement equipment utilizing traceable measurement standards. This service provider utilizes metrological tools & processes to perform the calibration and ensure the readings produced by the measurement device are within the range of tolerance, or the legally acceptable range of variation from the true value. Once this process is complete, the service provider labels the equipment as “legal-for-trade”. Through regular inspections, calibrations and verifications, metrology helps detect and prevent any attempts to manipulate measurements for unfair advantage. Doing so ensures that consumers receive what they pay for without falling victim to deceptive practices. In this way, metrology also contributes to the broader economy by promoting confidence, encouraging increased consumption and economic growth. Moreover, metrology is crucial in maintaining a level playing field for businesses. Establishing a standardized measurement framework fosters fair competition and prevents unscrupulous market practices. Companies can rely on metrology to uphold integrity in their transactions, knowing that their competitors are subject to the same rules and regulations. This encourages a healthy and competitive market environment, benefiting businesses and consumers. Metrology Technology
Scale Theory

calibration

By June 3, 2024 0 Comments
Necessary Tools and Equipment for Calibration Calibration is a crucial step in ensuring the accuracy and reliability of your scale. Now that we’ve established its importance, let’s delve into the next phase: gathering the necessary tools and equipment to carry out a successful calibration process. To calibrate your scale correctly, you’ll need a few things. Grab yourself some calibrated weights, a clean cloth or brush, gloves and any specific tools recommended by the scale manufacturer. Different scales may require different calibration tools, so be sure to check the user manual or consult the manufacturer for guidance. Once you have gathered the necessary tools and equipment, creating a suitable calibration environment is important. Find a stable and level surface to place your scale on, away from any vibrations or drafts that could interfere with the calibration process. Ensure that the temperature and humidity levels are within the recommended range specified by the scale manufacturer. By creating an optimal calibration environment, you can minimize external factors that may impact the accuracy of the calibration results. Remember, a well-prepared calibration process sets the foundation for accuracy.
Scale Theory

weighing instruments

By June 3, 2024 0 Comments
SELECTION OF WEIGHING INSTRUMENTS:
The weighing instrument is the most important part of the weighment process and the selection of the instrument, therefore has to be done carefully. If the selection is not correct, the result of the weighment may give a wrong indication, thereby leading to an incorrect decision.
Selection criteria: The selection of weighing instrument depends on the weighment to be performed. Generally, three characteristics are considered; these are:
• The range and magnitude of the parameter to be weighed and the accuracy of the weighment (the instrument should have the range to cover effectively the range of the parameter).
• The resolution of the weighing instrument should be smaller than the minimum unit of weighment of the parameter. • Lastly and most importantly, the accuracy or uncertainty of the weighing instrument should comply with the accuracy requirement of the parameter to be weighed.
Understanding accuracy in weighment:
In order to select the correct weighing instrument, the implications of instrument accuracy on the weighment data and the effect it has on decisions taken based on the data must be clearly understood.
If the accuracy of a weighing instrument is ± 1g, this means that the value displayed on the instrument would be considered the correct value so long as the actual value of the measurement is within ± 1g of the actual value. In other words, if 10g is the reading displayed on a weighing instrument while making a measurement and if ± 1g is the accuracy of that instrument, then the actual value could be anywhere between 9g and 11g, including either 9g or 11g.
Scale Theory

load cell Drief

By June 3, 2024 0 Comments
What Causes Loadcell Drift?
Bending Loadcell drift can prove to be a potential setback for measuring. It is often hard to detect if a person lacks the means to test for significant voltage changes. With that said, We know potential causes for loadcell drift and how a person can identify them. Drift can cause your loadcell to not return to O in between weighings. That is a concern because the O baseline allows you to get accurate measurement each time. Bangle point Diaphragm Bending Multiple C
What Is Loadcell Drift?
Loadcell drift is when the scale in question fluctuate on weighing the same object, leading to inconsistent results. It can be hard to identify because the drift affects all of the measurements involved, making it hard to isolate. Bad loadcells can be replaced and wiring can be fixed, as long as you know where to make repairs. The best way to identify the cause is to note the area that is causing a drift. While the loadcell itself may have the problem, the cables connecting it may also create inconsistent measurements. The controller, wiring, external machine binding may be the source of the problem as well. These can include the bearings and shafts being affected. One way to find the weighing system aspect that is having a problem is to conduct an IT stability test using a Junction Box. The IT stability test tests the Junction Box, Relevant cable and any instrument attached to see if which of the three is causing the problem. The Weight and Voltage tests see if the force sensors or the loadcells are causing the drift. It checks the weight of each loadcell and compares it to a designated baseline. This allows you to determine which instruments need replacing. Return To Zero tests check the loadcell’s mV, store it to check it against the designated calibration and to see if the defaults are normal. The cell should return to a value of O when it has no weight on it. If it doesn’t, then the problem is with the cell itself.
Common Reasons For Loadcell Drift:
a) Loadcell Damage
b)Temperature Affects Loadcells
c) Moisture Damage to Industrial Loadcells
d) Static Electricity Loadcell Drift
Scale Theory

Creep

By June 3, 2024 0 Comments
Many factors can affect the results you obtain from your scale or balance, including the environment where you’re conducting measurements. It’s important to understand which weight fluctuations are caused by vibrations or air currents and which are caused by your equipment. One of the common causes of result changes is creep.
Creep: We define creep as the change that takes place in loadcell output while under load and with all environmental conditions and other variables remaining constant. Creep usually is measured with rated load applied (usually 90% to 100% of the capacity) and expressed as a percent of rated output over a specific duration. Here’s an example: let’s say a loadcell can handle 1000 kg, features an output of 4.00mV/V and the creep rate is 0.01%. 4.00*0.010.04. 0.04/1000 = 0.00004 mV/V. That means the output of 1,000kg could change by 0.00004mV/V (0.4kg) over thirty minutes. Keep in mind this is a basic theoretical example. Various outside influences such as temperature are not constant and require much more complicated math to estimate. 10 -6.005 Relative Response () -0.015 Time (minutes) Creep response and creep recovery response of a shear-beam load cell of capacity 17.8 kN, temperature: 19.6°C Essentially, a loadcell measures weight by measuring the deformation of the loadcell caused by the item being weighed. The loadcell is designed to withstand such changes but can take some time to fully deform then recover. These changes are what we call creep. The deformation and recovery can lead to fluctuations in the reading of the weight. The difference between drift and creep:
They sound similar and are often confused, but creep and drift are not the same. Drift is caused by the scale or balances recording changes in weight resulting from environmental factors that affect the sample’s mass. Creep is specifically the deformation and recovery of material, in this case the loadcell.
Scale Theory

Tank Weighing Scale

By June 3, 2024 0 Comments
TYPES OF LOADCELLS USED IN TANK WEIGHING SYSTEM TANK WEIGHING ASSEMBLY LOADCELL:
A tank weighing assembly refers to the complete setup or system used to measure the weight of a tank accurately and a tank-weighing assembly loadcell is designed as a key component for measuring the tank’s weight and its contents. These loadcells are engineered to withstand heavy loads and harsh environmental conditions in various industrial settings. The loadcells are strategically placed underneath the tank as individual cells or an integrated system to accurately sense and convert the applied force into an electrical signal. This signal is then transmitted to the digital indicator or computer system, which is processed and displayed as the tank’s weight. SHEAR BEAM LOADCELL: A shear beam loadcell consists of a strain element that deflects under load. The load is applied perpendicular to the strain element, causing it to bend. The deflection is detected by strain gauges and converted into an electrical signal, providing a weight reading. These loadcells offer excellent stability and are suitable for various tank sizes and capacities.
CAPACITIVE LOADCELL: Capacitance is a fundamental electrical property of all objects, defined as the ratio of the electric charge stored on an object to its associated voltage and capacitive loadcells employ changes in capacitance to measure weight.
They consist of two parallel plates, one fixed and the other attached to the load. As the load is placed or removed, the distance between the plates changes, resulting in a shift in capacitance. This change is converted into an electrical signal providing a weight measurement.
DOUBLE-ENDED
SHEAR BEAM LOADCELL: A double-ended shear beam loadcell is similar to shear beam loadcells but has load application points at both ends. This design provides improved load distribution and reduces the possibility of side-loading errors. These loadcells are commonly used in tanks where precision and accuracy are crucial. They are known for their robustness and ability to withstand heavy loads, making them suitable for large tanks and industrial applications.
Scale Theory

Weighing scale Accuracy

By June 3, 2024 0 Comments
Ensuring Accuracy and Traceability of Weighing Instruments (by Georgia Harris): Operators of weighing devices must have confidence in the accuracy and traceability of their weighing equipment. To develop this confidence, they need to be able to evaluate scale and balance service companies and calibration organizations that they engage. Assurance of accuracy and traceability are the two most important factors in characterizing the quality of measurement results. Measurement quality is partially determined by, and critically dependent on, these two vital factors. Defining Accuracy and Traceability- The following definitions are published by the International Organization for Standardization (ISO) in the International Vocabulary of Basic and General Terms In Metrology, 1984. Accuracy The closeness of the agreement between the result of a measurement and the (conventional) true value of the measurand. Or, the ability of a measuring instrument to give indications approaching the true value of a measurand. In simple terms, Accuracy refers to whether or not a measurement is correct, free from error, and reflects the true value. ASTM standard E 456, Terminology Relating to Quality and Statistics, defines “Accuracy” as “the closeness of agreement between a test result and an accepted reference value.” Since nothing is ever perfect, We estimate by repeated measurements, how close our measurements are to the true values. This is critical for assessing accuracy. Traceability-The property of a result of a measurement whereby it can be related to appropriate standards, generally international or national standards, through an unbroken chain of comparisons. Traceability implies an ability to relate individual measurement results through an unbroken chain of calibrations to a common source. In the United States, this ultimately leads back to national standards maintained by the National Institute of Standards and Technology (NIST). This unbroken chain constitutes an “audit trail.” To support a claim of traceability, an adequate audit trail must be established using documentation. This documentation provides acceptable evidence that becomes important when using calibration services and when evaluating the traceability of test weights used to establish the accuracy of weighing equipment.
Scale Theory

Electronic Weighing Scale

By June 3, 2024 0 Comments
Electronic weighing systems are used in industries and business establishments for weighing and segregating materials accurately for process sales.
The main advantages of an electronic weighing system when compared with mechanical weighing systems are: compactness and small size independent of capacity, Ruggedness and high dependability, High speed of response and rapid weighing, Good accuracy, Excellent flexibility to monitor multiple loads, Analog and digital with print-out facility, remote indication and parallel display, Online processing through computer. The electronic weighing system comprises the basic loadcell, suitable signal conditioners and output recorders / indicators giving both the analog and digital output for further processing. The signals from the loadcell are amplified and fed to analog / digital converter, which provide an output in the digital format for display/printing/processing etc. The strain gauge based loadcell is the most popular weight transducer used in the electronic weighing system. Process of Manufacture: The manufacturing process involves the assembly of loadcell, electronic circuits and electro mechanical hardware. Subsequently, the electronics assembly-the ICs, transistors, diodes, resistors, capacitors, transformers, coils, relays and potentiometers are assembled on PCBs as per design. The assembled PCBs are tested for performance. Subsequently the electronics assembly along with electromechanical assembly, hardware such as connectors/switches, terminals, displays, meters are assembled and housed in a metallic / fibre / plastic case with an appealing front panel. Finally the assembled unit is calibrated and tested as per the design specification. Pollution Control: The following steps are suggested which may help to control pollution in electronics industry wherever applicable. In electronics industry, fumes and gases are released during hand soldering / wave soldering / Dip soldering, which are harmful to people as well as environment and the end products. Alternate technologies may be used to phase out the existing polluting technologies. Numerous new fluxes have been developed containing 2-10% solids as opposed to the traditional 15-35% solids. Electronics industry uses CFC, Carbon Tetrachloride and Methyl Chloroform for cleaning of printed circuit boards after assembly to remove flux residues left after soldering and various kinds of foams for packaging.

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