Throughout the years, we have come across many customers who aren’t sure if they should be using an accredited calibration lab for their aircraft equipment or not. The short and easy answer is: it depends. What is your line of work? What does the FAA require? What type of quality do you expect in the calibration work? Based on your answers to these questions, you can get varying answers. Before you decide, however, whether you need an accredited calibration lab to work on your equipment, or need a full out accredited calibration, it’s best to understand what all of this even means.
In this whitepaper, we will take a look at what an accredited calibration lab is, what types of work an accredited calibration lab can produce vs. a non-accredited lab, what the benefits are to using an accredit calibration lab and, finally, what your alternative choices are.
A calibration lab is only considered accredited after it has been evaluated by a third-party organization and deemed competent and compliant with the ISO/IEC 17025 standards. These standards, similar to those of ISO 9001, consist of quality management system requirements, but with a deeper technical focus. ISO 17025 accreditation requires the lab to have adequate equipment to perform tests and calibrations. The lab must also have personnel who excel in technical competence and that are proficient in performing tests and calibrations. Assessment for accreditation is broken down into three focal areas, personnel, environment and traceability. If these three areas meet the required standards, the laboratory is then recognized as having the highest level of technical competency and is granted accreditation. Accreditation is then maintained through proficiency testing, which is performed on a regular basis to ensure technical competence.
As stated above, the three key factors that make-or-break accreditation for a lab are the people they have working in it, the environment in which they work in and the traceability of the laboratory equipment. Each focal area has a set of requirements it must meet to be considered ISO 17025 standard, therefore all three are accessed in detail:
Laboratory workers are assessed on technical competence of the equipment and equipment usage. Accreditation requires personnel to understand how to operate all the equipment they use and how it affects the calibration results. In addition, workers need to be capable of calibrating equipment and fully understanding the results. Although these requirements seem pretty basic, they are essential. A laboratory will only be approved to perform accredited calibrations if the personnel understand the measurements they are taking, why they need to take them and how to properly evaluate the results of the measurements to determine the correct operation of the instrument.
Accrediting bodies determine if the lab personnel meet all the requirements listed by supervising and conducting internal and external audits. With interviews and close observation, the accrediting bodies can verify if the laboratory workers are competent and complaint with ISO 17025 standard.
Laboratory environment is assessed by its conditions; temperature control, humidity and barometric pressure are all conditions that are taken into account when assessing for accreditation. It is vital that these conditions, along with sound and vibration levels, are constantly monitored to ensure they do no invalidate results of calibrations or the quality of any measurements. Laboratories are also required to pay close attention to biological sterility, dust, electromagnetic disturbances and radiation. Regulatory housekeeping of the lab is also crucial.
Accrediting bodies will decipher from previous records if the laboratory has complied with the listed requirements. If all ducks are in a row, the laboratory environment will be recognized as meeting the ISO 17025 standard.
The final step in the accreditation process is analyzing equipment traceability. All equipment used to calibrate instruments and conduct measurements must be traceable through an unbroken chain of calibrations or comparisons linking to relevant standards of International System of Units (SI). Calibrations certificates issued through the lab should contain all measurement results, including measurement uncertainty.
Accrediting bodies will often rely on the National Institute of Standards and Technology (NIST) traceable number for each calibration certificate as evidence of traceability. If the laboratory is in compliance of the traceability requirement, it is then deemed up to ISO 17025 standard.
The Scope of Accreditation is the official and detailed document containing a list of activities and calibrations a lab is accredited to perform. The purpose of this document is to define specific areas and to provide the user of an accredited laboratory with a description of the specific calibrations covered by the accreditation. It is considered to represent the core of the accreditation process. This document will usually be several pages long and can be found with the laboratory’s Certificate of Accreditation. Both the Certificate of Accreditation and the Scope of Accreditation will have an expiration date of two years. Throughout the two year period, the laboratory is required to demonstrate compliance to the management and technical quality systems, along with the full technical competence observed during the assessment period.
The content of the scope of accreditation is verified during the assessment process by the accrediting body to ensure the personnel and laboratory are competent and complaint with the ISO 17025 standard. As previously mentioned, the accreditation assessment includes demonstration of testing skills. These skills are performed during assessment under observation and then are added to the scope of accreditation if deemed compliant with ISO 17025 standard. The scope will usually include parameter/equipment, measurement range, Calibration and Measurement Capability Uncertainty (CMC) and comments on the techniques used to perform the calibrations.
It is very important to note that the content on the scope of accreditation does not include all the laboratory’s capabilities, only the ones they have been accredited for. For example, an accredited lab can have x, y and z listed on their scope of accreditation. This means that those three areas were observed by the accrediting body during the assessment process and then deemed complaint with ISO 17025 standard. However, say you request a service for w. The accredited lab can perform this service, but it will be considered “commercial calibration.” Commercial calibration doesn’t mean that the laboratory is incompetent within this area, it just means the service was not observed by the accrediting body during assessment. This could be due to a variety of reasons, particularly the laboratory requesting a limited scope of accreditation because of costs or for certain technical reasons.
The answer to this question is simple. As previously discussed, the assessment for accreditation is quite rigorous. There are a handful of factors that play into a laboratory being deemed as competent and compliant with ISO 17025 standard, but it is these factors that ensure quality results. Accrediting bodies use ISO 17025 standard to specifically assess factors such as, staff competence, validity of test methods, traceability of measurements and calibrations to national standards, appropriateness and conditions of testing environment, sampling and handling of test items, maintenance of equipment and quality assurance of data.
When choosing a laboratory for maintenance of your equipment and instrumentation, it is essential to look for a lab that can meet your needs and also give you accurate results. Accredited calibration labs are guaranteed to have personnel with the highest level of technical competence, a monitored laboratory environment and precise equipment traceability. Unlike laboratories without an accreditation certificate, accredited labs live, breathe and eat maintenance. Through proficiency tests and internal checks, accredited laboratories are continually being assessed to ensure they stay within ISO 17025 standard. It is important to note that not all unaccredited laboratories are equal, therefore not all calibrations are equal. This is why choosing an accredited calibration lab is crucial; it will automatically guarantee accuracy of calibrations.
Accrediting bodies closely observe laboratory personnel to ensure they understand how to operate the equipment and how the equipment affects the calibration results
Accredited laboratories are required to meet the highest industry standard, ISO 17025
When equipment and instrumentation is properly maintained, risks of calibration inaccuracy are minimal
Accreditation requires that all the equipment used to calibrate items must be traceable through an unbroken chain of calibrations.
The assessment process ensures that the labs environment does not invalidate the results of calibrations or adversely affect the required quality of a measurement
Accredited labs are required to calculate measurement uncertainty for each parameter. This is required to be listed on the labs scope of accreditation.
The alternative to using an accredited calibration lab would be to use a laboratory that is unaccredited and performs commercial work. Another option would be to use the equipment’s manufacturer. Although both these alternatives can perform the same calibrations as those an accredited lab can perform, it is best to remember why exactly a lab has been granted accreditation in the first place. Unaccredited laboratories and manufacturers are not observed by an accrediting body and are not required to meet high level of standards.
When choosing an accredited calibration lab, all cards are laid out on the table – there are never any surprises or unknown areas. Accredited labs undergo an extremely thorough assessment period which requires them to meet all standards before being deemed as accredited and compliant with ISO 17025. The International Organization of Standards created 17025 as a recognizable global standard of quality and conformance. During the accreditation assessment, a Scope of Accreditation is created to show exactly what a lab is accredited to do.
Because of this voluntary process, accredited calibration labs guarantee competent personnel, a monitored laboratory environment and equipment traceability through NIST. By choosing an accredited calibration lab, you are ensuring calibration accuracy. It’s important to note that accuracy in calibrations is crucial when it comes to proper operation of equipment and the safety of personnel operating the equipment. If calibrations are off, it could put a handful of people at risk. The risk of inaccurate results, along with process variance, inappropriate testing conditions, and poor documentation, are substantially reduced when working with an accredited laboratory. It is also important to remember that not all unaccredited laboratories are equal, therefore not all calibrations are equal.
By choosing an accredited calibration lab, you are guaranteeing yourself accuracy, compliance and satisfaction.