Accurate weight measurement is a cornerstone for efficiency, safety, and precision in industrial operations.
At the heart of this process are load cells and crane scales. Understanding the necessity of accurately calibrating these devices is essential for ensuring functionality and reliability in industrial processes that depend on precise measurement.
In this guide, you will find everything you need to know about load cell calibration, why it’s crucial to keep crane scales accurate, and practical tips for their maintenance.
What is a Load Cell?
A load cell is a type of transducer specifically designed to convert force or weight into electrical signals. This device is indispensable for accurate weight measurement in various settings, from laboratory environments to large-scale industrial applications.
Typically available in various types like strain gauge, hydraulic, pneumatic, and capacitive, load cells cater to specific operational needs.
The strain gauge type, commonly used, operates by detecting strain in its gauges when subjected to force, altering electrical resistance to generate proportional signals.
Load cell calibration fine-tunes these devices, eliminating offset errors to maintain accuracy. This process guarantees the integrity and efficiency of industrial processes that rely on precise weight assessment.
How to Calibrate a Load Cell?
The steps to calibrate a load cell are as follows:
Step 1
It begins with applying known loads across the load cell’s capacity range, employing calibrated weights or force standards for precision.
Step 2
Next, thoroughly compare the load cell’s output readings with the anticipated values corresponding to the applied loads. Any disparities detected during this comparison phase are meticulously noted and analyzed to pinpoint deviations.
Step 3
Adjustments are then made to the load cell’s settings or configurations to minimize errors and align its readings with the expected values.
This is a crucial phase where we tweak the settings to reduce any errors. The goal here is to ensure that the load cell’s readings closely match the expected values, enhancing its performance and accuracy.
Regular calibration is more than just playing safe; it’s a proactive step to prevent future inaccuracies. Factors like environmental changes or natural wear and tear of components can lead to slight deviations over time.
Can Load Cells Drift or Lose Calibration Over Time?
Like any precision instrument, load cells may experience drift or lose calibration over time. This gradual change in output signal, known as drift, can lead to inaccuracies in weight assessments.
Determining how often load cells should be calibrated depends on usage, industry standards, and manufacturer recommendations. It is important to consider that critical applications naturally will require more frequent checks.
At Massload, aligning with the requirements of the industries we support, we recommend an annual calibration schedule to maintain optimal accuracy and reliability in weight measurements.
All calibrated weigh products manufactured at Massload carry a label indicating the calibration date and recommended re-calibration date.
What are the Consequences of Using Uncalibrated Load Cells?
The usual consequence of uncalibrated load cells is the potential inaccuracies and deviations in weight measurements, leading to compromised quality control, reduced efficiency, and safety hazards.
These inaccuracies can spread throughout the production line, impacting product quality and final outputs and, even worse, generating rework and financial loss.
Furthermore, uncalibrated load cells might result in misinterpretation of data, leading to erroneous decision-making, potential product defects, and increased operational costs due to rework or rejected products.
Not paying attention to these inaccuracies can also be a safety issue, potentially leading to accidents or equipment failures.
What is a Crane Scale?
A crane scale is a specialized weighing device engineered for lifting applications. It uses strain gauge technology to convert the force exerted during lifting into measurable weight readings.
It’s designed to withstand harsh working conditions, ensuring accuracy and reliability.
Typically suspended from cranes or hoists, these scales feature sturdy construction and load-bearing capabilities suitable for diverse load capacities, ranging from small loads to heavyweights.
Crane scales can also be equipped with features such as:
- Digital displays
- Remote controls
- Durable enclosures
To facilitate ease of use, data readability, and protection against environmental elements.
How to Maintain Crane Scale Accuracy?
The crane scale calibration process encompasses the following steps:
01. Routine Scale Check-up
These checks involve thorough examinations for signs of wear, corrosion, or damage in crucial components such as load cells, hooks, and cables.
Adhering to the manufacturer’s guidelines aids in verifying and adjusting the scale’s accuracy.
02. Maintenance
Regular cleaning is paramount to remove debris, dirt, or contaminants that could compromise the scale’s performance.
Lubricating moving parts, including bearings or pivots, ensures smooth operation and extends the scale’s lifespan.
03. Scale Protection
Shielding the scale from extreme environmental conditions, such as rain, excessive humidity, or drastic temperature variations, is essential to preserving its accuracy over time.
04. Periodicity Verification
Periodic verification against calibrated weights or standards ensures the scale remains within acceptable tolerance levels.
Conducting load testing using calibrated weights on a regular basis serves to verify accuracy and promptly detect any deviations.
05. Proper Handling
Proper storage and handling practices, which involve avoiding shocks or impacts and preventive maintenance on mechanical parts, significantly contribute to maintaining crane scale accuracy.
06. Ongoing Training
Training operators on proper usage and handling techniques ensures precise measurements as well as increasing workplace safety.
07. Maintenance Records
Maintaining comprehensive records of maintenance schedules and performed tasks is crucial.
These records help to track the scale’s condition, preventing possible downtime and enabling interventions to be planned instead of just acting when a problem occurs.
What is the Accuracy of Crane Scales?
Crane scales often specify their accuracy levels, typically expressed as a percentage of the applied load or as a division of the total capacity of the scale.
Their accuracy may vary due to several factors that range from design intricacies to construction, calibration precision, and environmental influences.
At Massload, our crane scales boast an accuracy range from 0.1% to 0.5% FS, varying depending on the product’s specific model and intended application.
It’s also important to note that actual accuracy can be influenced by other variables that will emerge during the use of the equipment, such as load distribution and movement dynamics.
Maintaining consistent accuracy in crane scales is achieved through regular calibration.
What is the Difference Between Two-point or Multipoint Calibration?
Load cell calibration methods typically fall into two categories: two-point or multipoint calibration.
Two-point calibration, also called single-point calibration, entails adjustments at two reference points, often at zero and a single reference load. This method compensates for potential offsets and linear errors, improving load range accuracy.
However, it might not address nonlinearities or variations between these two reference points.
Multipoint calibration involves adjustments at multiple reference points throughout the load range. Which considers non-linear behaviors across the load cell’s entire capacity, resulting in a more thorough calibration, but will also require more time and resources.
How to Choose The Correct Type?
In order to choose the most appropriate calibration, it is necessary to consider various factors, such as the application’s precision requirements, load cell characteristics, and industry standards.
Two-point calibration offers improved accuracy and is suitable for applications with known deviations at zero and full-scale loads.
For applications demanding high precision and accuracy across the load range, especially where nonlinear behaviors are critical, multipoint calibration can be advantageous.
Considering the load cell’s linearity, sensitivity to errors, and regulatory compliance aids in determining the correct calibration type.
It’s essential to note that while multipoint calibration offers superior accuracy and thoroughness by addressing nonlinear behaviors comprehensively, it generally entails higher instrumentation costs compared to single-point or two-point calibrations.
Before making your decision, remember to consult the calibration standards and manufacturer recommendations applicable to your industry and product.
And, of course, Massload’s expert advice is always available to assist you in making an informed decision. Get in touch, and we can sort out your questions together.
Does Calibration Need to Be Performed By a Specialist?
Load cells and crane scale calibration can be managed in-house or outsourced, with the choice influenced by factors like resources, expertise, and calibration complexity.
In-house calibration offers convenience and saves money, granting control over the process and allowing swift adjustments and frequent checks. However, it necessitates skilled personnel, which can be hard for some organizations. In addition, maintenance, certification, and quality controls may be required for reference loads used for calibration.
On the other hand, outsourcing calibration to specialized companies gives you access to advanced equipment, calibrated standards, and skilled professionals who are working with a wider spectrum of scales.
It’s an option that guarantees compliance with industry standards and regulatory requirements, especially when we are talking about critical processes.
Before deciding which option is best for your company, it is important to consider your budget, the frequency with which this service needs to be performed, and whether you have this expertise in-house.
Maintaining load cells and crane scales calibrated is what guarantees that your operations are running smoothly and that you and your team are getting all the measurements correct, especially considering that this data serves as a foundation for engineers, enabling optimal equipment performance and extended lifespan.
Failing to keep this process up to date can result in inaccurate measurements, financial loss, safety gaps, equipment damage, and more.
Our recommendation of an annual calibration schedule balances precision and operational efficiency, empowering industries to maintain accuracy without compromising productivity.
Precision Partnerships: Keep your equipment accurate with Massload’s Calibration Services
At Massload Technologies, our commitment to accuracy, reliability, and customer satisfaction drives our calibration services to meet diverse industrial demands.
Our state-of-the-art equipment highlights our comprehensive capabilities in crane scale calibration:
- For load cells: Utilizing a 100,000-pound compression force calibration tester/machine with laboratory-grade reference standards.
- For crane scales: Employing a 150,000-pound tension force calibration tester/machine with laboratory-grade reference standards.
When industrial clients partner with us, they get precise calibration, cutting-edge technology, and unwavering dedication to precision.
