Manufacturing machine calibration ensures accuracy and consistency for measuring tools by comparing against reference calibrating equipment and then making adjustments as necessary. The primary significance of calibration is that it maintains accuracy, standardization and repeatability in measurements, assuring reliable benchmarks and results. Without regular calibration, equipment can fall out of spec, provide inaccurate measurements and threaten quality, safety and equipment longevity.
Accuracy in manufacturing is a key metric when it comes to the quality and performance of a process or finished product. If a part is not produced within a customer’s required specifications, which are determined by the application of the product, there are more than likely going to be negative consequences. So why is calibration important? The importance of accuracy in manufacturing illustrates the importance of calibration as well, since manufacturing equipment must be correctly calibrated in order to perform to specifications. Without properly calibrated equipment, it’s impossible to achieve the necessary level of accuracy and ISO quality requirements.
What is calibration in manufacturing?
The purpose of calibration is to verify that equipment still functions within the pre-determined specifications. This is extremely important as it helps ensure what the machinery produces continues to fit within the specified tolerances. Without calibration, there is the risk of producing parts that don’t fit together properly or otherwise fail to meet quality standards.
There are two main types of machine calibration commonly used by technicians:
- Absolute calibration: This method involves calibrating the instrument based on a known reference value, such as calibrating a scale with a weight known to weigh a specific amount.
- Relative calibration: On the other hand, relative calibration is done by matching the instrument values to another instrument known to be accurate.
Why is accuracy critical in manufacturing?
The most important reason that accuracy is a critical standard in manufacturing is the quality and safety of the finished part. Inaccurate parts – those outside of the required tolerance – cannot be used because the likelihood of them functioning properly is very low. For example, a misalignment of 1 millimeter in a medical device can lead to a failure in the field, triggering liability and expensive recalls. When word of these product failures make it into the news, it can result in serious reputational damage that a manufacturer may not be able to overcome.
In addition to quality, performance and safety, inaccurately manufactured products caused by uncalibrated machinery can result in the following:
High rates of rejected parts — Improperly calibrated machinery creates inefficiencies in production and results in wasted materials. If your quality control processes don’t reject inaccurate parts, your customers surely will.
Cost and time overruns — High numbers of rejected parts will require either additional production to replace them or additional finishing processes to bring them up to spec. These requirements will extend production time and threaten deadlines. They will also add process costs that cannot be passed on to the customer.
Make good requirements — If inaccurate parts are delivered late, the customer may require additional production at no cost to them or worse, may choose to take their business elsewhere.
Reputation damage — Unhappy customers may leave poor online reviews about your services, putting your brand and your pipeline of new customers in danger.
The importance of calibration in manufacturing
What is the importance of calibration in quality assurance for manufacturers? Calibration of equipment plays a major role in avoiding the production of inaccurate parts, so the advantages of industrial calibration for your machinery and measuring equipment cannot be overstated. There are several facets of calibration in manufacturing but in general, calibration is important in these two key areas:
- Calibration for measuring equipment ensures that your quality control processes are accurate, and that you’re not accepting parts that should be rejected.
- Calibration for manufacturing machines creates a more efficient process by ensuring that equipment is operating as expected. Improperly calibrated equipment will result in unpredictable manufacturing results and inaccurate products.
- When equipment is properly calibrated, it continues to provide consistent performance. This leads to less waste, fewer production delays and lower rates of rework.
- With the most accurate measurements possible, the data collected throughout the manufacturing process can be considered reliable. When you can count on your data, you can have better process control and more informed decision-making.
- Safety equipment such as pressure gauges and temperature sensors are more effective at creating a safe working environment when they are precisely calibrated.
- Most automated or robotic systems require precise calibration to provide the most efficient performance when it comes to pick-and-place or assembly tasks. Otherwise, time is wasted as workers need to intervene and adjust.
- Calibration and maintenance go hand-in-hand because it’s critical to have instrument readings you can trust when undertaking preventive maintenance tasks. Without accurate readings from your instruments, it is difficult to get the best performance out of your equipment. Accuracy is critical for precision maintenance because it ensures predictable, consistent results no matter how large or small the activities may be.
Types of equipment calibration
Because there are so many conditions that can impact the performance of manufacturing equipment, there are many types of calibration for the accuracy of these machines. Some of the most common examples include:
- Pressure calibration: Pressure gauges and sensors need to be calibrated to ensure they provide the most accurate readings and prevent overloading or loss of efficiency.
- Temperature calibration: The temperature of equipment can have a tremendous impact on its performance, and thermostats and thermometers must be able to measure it with accuracy.
- Dimensional calibration: Tools that measure length, width and other physical dimensions must be checked to ensure they are accurate. These include calipers, micrometers and others.
- Electrical calibration: Checking multimeters, current testers and other instruments for the measurement of electrical activity is vital for keeping machinery in good condition.
- Flow calibration: Controlling the flow of liquids and gases means having the correct readings from flow meters and regulators.
- Force calibration: Devices such as load cells and torque wrenches must be able to measure forces with precision to determine how severely equipment is being used.
- Mechanical calibration: Instruments that measure mechanical properties such as mass, volume, density, force, torque, flatness and vibration must be kept properly calibrated to help technicians make decisions about maintenance.
How does calibration work?
In general, there is a standardized process that technicians follow when calibrating machinery:
Step 1: Choosing a standard — Calibration for maintenance begins with technicians determining the reference standard against which the equipment will be checked. When calibrating against another instrument, the reference standard should have a higher level of accuracy than the instrument being calibrated.
Step 2: Comparing measurements — Under controlled conditions, the device being calibrated is tested against the reference standard. The conditions need to be strictly controlled to prevent any outside factors from skewing the results. Measurements are taken, and any deviations from the standard are recorded.
Step 3: Adjusting the equipment — Based on any discrepancies found in the equipment, adjustments are made and the machinery is recalibrated to match the accuracy of the reference standard.
Step 4: Documentation and certification — The final step of the calibration process is to document the results of the calibration efforts and issue the certificate of calibration. This is to certify that the equipment meets all the required calibration standards. The use of digital solutions and software can help technicians track calibration history as well as automatically schedule the next intervals and keep all certifications on file.
Common calibration challenges in modern plants
Implementing a successful calibration program in a production facility can be more challenging than it looks at first. However, with a centralized system in place, manufacturers can avoid or solve some of the most common issues they might have, such as:
- Insufficient training — Technicians who are not adequately trained in the proper calibration procedures won’t be able to achieve the plant’s objectives as intended.
- Time constraints — There may not be enough hours in the day to accomplish absolutely everything that needs to be done, but a centralized solution can ensure that there is a schedule in place that prioritizes the work that needs to be done when it’s needed the most.
- Ignoring small deviations — Teams that allow deviations to slip through because they’re believed to be insignificant are only introducing risk into the process. The culture surrounding calibration should make it clear that all deviations should be addressed, no matter how small.
- Failing to keep calibration records — Without a central log of all calibration activity, there’s the chance that work will be duplicated unnecessarily or overlooked altogether. The right software system can help keep everything straight.
Calibration’s role in predictive maintenance
Predictive maintenance protocols call for equipment to be connected with sensors that provide a steady stream of information about machine health and performance. Conducting routine calibrations provides another source of valuable data that can help technicians identify patterns and schedule maintenance before the equipment is at risk of failure. In turn, the data received from IIoT-connected machines can be used to schedule manufacturing calibration activities and prevent equipment from falling out of spec.
Calibration services from ATS
As an industry-leading industrial maintenance services provider, ATS offers calibration services as part of our comprehensive maintenance solution. We provide our customers with standard maintenance to maintain correct calibration, calibration testing, corrective maintenance and more keeping them compliant with formal system requirements from ISO-9001, IATF-16949, AS9100, to special processes like NADCAP. Our labs operate under an ISO/IEC 17025 quality management system and have NIST-traceable measurement systems. This accreditation guarantees the technical competence of our people and the integrity of our systems. To learn more about how these maintenance and calibration services can help mitigate risk and drive continuous improvement in your operations, contact us today.
