HomeAdviceWhat is Calibration and Why Have It Done?
Ever wondered if your business needs calibration, or even what calibration is? With an increasing demand for reliable and trustworthy measurements, calibration needs to be an essential part of your quality management strategy.
Read on to learn about the calibration process, some of the different types of calibration and calibration standards, and the benefits of regularly calibrating your test instruments.
What does calibration mean?
Calibration is the process of checking measuring equipment or instruments by comparison with a standard (another instrument or artefact of known accuracy and properties). The instrument or artefact used in the calibration process must in turn be calibrated with equipment that has an unbroken chain of calibrations back to international standards.
Historically, traceability was back to National Standards, but a calibration standard is now an internationally recognised value. The traceability to international standards uses the International System of Units (SI).
Calibration technically does not include adjustments, but adjustments are made when possible to bring the instrument test equipment back into predetermined tolerances and specifications.
The process checks whether the values are within an acceptable range (tolerance level) in relation to the specific application.
Why is calibration important?
Even though your measuring tool may be working fine, how do you know the readings it’s displaying are correct? In the simplest form, if you buy 1kg of apples, how do you know you have 1kg and not 0.9kg or 1.1kg? Furthermore, if you buy 1kg of apples from another country you need to know it’s the same as buying 1kg in the UK.
This also applies for more critical scenarios. For instance, hot food must be maintained at or above 63°C before service to prevent the growth of harmful bacteria. Without a calibrated probe thermometer, it’s impossible for food industry professionals to check and monitor the temperature of food with complete confidence.
Sensors and electronics in regularly used test instruments are prone to drift over time, leading to measurement errors, safety hazards, and quality issues. That’s why calibration is a vital step in ensuring your test instruments are measuring as they should be, providing the foundation of confidence in the data and measurements that inform your decisions.
How often should calibration be done?
The main questions to ask here are how important are the measurements to my process or product and how likely is it my equipment will drift out of specification between calibrations?
Annual calibration is the most common requirement for measuring equipment, but sometimes it’s possible to increase this further to 18 or 24 months. Stable standards like weights, might only require calibration every three to five years, depending on how they are used and how often. This includes what the environment they are used in — weights that are only used in a clean laboratory will of course be less susceptible to dirt and therefore change. Weighing scales and balances that are product or process critical (especially ones with a higher resolution) will require calibrating every six months or less.
It’s often quite easy to set up a simple user check, either before the equipment is used or once a week, etc. For example, if you had a weighing scale that weighs up to 2kg, you could purchase a 2kg and 500g calibrated weight to check the scale with. This can be helpful to increase the calibration cycle intervals, while maintaining confidence in the measurements you are taking. Although this isn't a replacement for a full and proper calibration across the full range of an instrument by an experienced engineer, it will help to highlight when there is a potential problem lurking.
For more critical applications or high-risk environments such as medical devices and pharmaceuticals, shorter intervals may be required.
Ultimately, there is no “one size fits all” answer. It’s always wise to check the manufacturers’ specifications (usually located in the manual), which indicate how often to calibrate their tools.
Other factors to consider when reviewing calibration frequencies include:
Recent damage or repairs: It’s always best practice to have your equipment calibrated right after any damage or repairs. For instance, higher resolution weighing equipment, which is more sensitive to movement and knocks.
Industry standards: Industries such as aviation and healthcare that often carry out critical measurements have regulatory bodies that mandate the calibration of specific equipment and instruments. For example, blood pressure monitors. Understanding and following these strict regulations and standards is also vital for avoiding legal and compliance issues.
Environmental conditions: The accuracy of your test instruments can also be impacted by the operating environment in which they are used. Factors such as humidity, temperature, exposure to chemicals, and dusty or dirty areas can necessitate greater maintenance (including calibration) to ensure optimal performance.
Gauge Blocks Used For Calibration.
How much does calibration cost?
Again, it’s impossible to define a “calibration price”, as each instrument undergoes a different calibration process. Some calibrations are more time-consuming than others, especially for complex instruments like tensile testers and permeability analysers that require an engineer with specific technical expertise.
How quickly you need your measuring equipment back will also affect the final calibration cost. AML Instruments offer both on-site and off-site calibration services, with many test instruments suitable for our express 24-48 hour service (pre-booking required).
For instruments such as multimeters and torque wrenches, we also provide a “Calibrate While You Wait” service, where we arrange a date and time for you to bring your tools to our in-house laboratory in Lincolnshire. You can sit back and relax with a cuppa, while we get to work ensuring your instruments are measuring as they should be.
The type of calibration standard you choose to have your equipment calibrated too will also affect the bottom line, but which is right for you?
Does my business require traceable or UKAS accredited calibration services?
AML Instruments offer two types of calibration: traceable calibration services and UKAS ISO 17025 accredited calibration services. UKAS is the United Kingdom Accreditation Service who assures the requirements of ISO 17025 are met. UKAS ISO 17025 accredited calibrations, have been fully assessed by UKAS from a quality and also technical perspective.
All calibration services must be able to establish traceability back to National & International Standards. This is the minimum requirement for any calibration service. We use the term traceable calibration to describe non-accredited calibrations.
Traceable calibrations are the right choice for the vast majority of our customers and meet the requirements of ISO 9001, AS 9001 (aerospace quality management system), and many other standards. Correctly performed traceable calibrations will be technically identical to UKAS ISO 17025 calibrations, but without the auditing and assessment process performed by UKAS.
UKAS ISO 17025 accredited calibrations can be advantageous for certain industries such as automotive where their standard IATF 16949 states all calibration where possible must be ISO 17025 accredited calibrations. It’s also useful to have accredited calibrations performed in many other industries where the calibrations performed will come under additional scrutiny.
We are continuing to grow our accredited calibration scope with Force and Universal Testing Machines being next on the list to be assessed by UKAS.
Whether you opt for traceable or UKAS calibrations depends on your specific requirements, but either way it’s essential for maintaining measurement accuracy and quality in many industries in the UK.
If you require advice on which type of calibration you require, we’re happy to help.
What type of industries require calibration services?
Many industries require professional calibration services to ensure their measuring devices are accurate. These include:
Is calibration a requirement of the ISO 9001: 2015 quality management system?
In a word, yes! If you take any measurements in your manufacturing, service, or testing processes, the equipment used must be calibrated on a regular basis and these calibrations must show traceability back to national and international standards.
Detailed records must be held recording the performance of the equipment being calibrated. These records or calibration certificates must be reviewed and retained in accordance with the requirements of your quality manual / procedures.
Benefits of regular calibration
Calibrating your test equipment is a no-brainer for many reasons:
Maintains the integrity of your measurements.
Maximises process efficiency and minimises waste,
Helps prolong the life of your testing equipment.
Saves money and prevents downtime by identifying potential problems in equipment before they turn into costly failures.
Safeguards your operations and ensures products are safe for consumers.
Provides traceability, giving businesses and consumers a higher confidence level in their measurements. For clarity, all calibrations carried out by AML Instruments are returned with a traceable calibration certificate to prove your measuring device has been calibrated.
Ensures compliance to industry regulations (if applicable).
Prevents extended downtime.
Explore AML Instrument’s specialised calibration services
Calibration services are vital for businesses worldwide, helping to eradicate measurement flaws and uncertainties from harming your processes and quality output.
AML Instruments can calibrate more than 500 different instruments, all to ISO 9001 approved procedures. As the only UKAS calibration accredited laboratory in Lincolnshire, you can trust AML Instruments to deliver the level of accuracy and traceability your company demands.
If you’re unsure what type of calibration you need, how frequently it should be performed, or would like to find out about our comprehensive range of calibration services, please contact our friendly, knowledgeable team today.
