How well do you understand the distinction between measurement equipment calibration and verification? The two terms are frequently used interchangeably between service providers, which can lead to misunderstandings about what each term actually means. It's a question we get asked a lot here at Status, and it's a good one. In this section, we'll take a closer look at both of these terms and explain what they mean.
Verification, also known as certification, is the process of determining whether or not a CMM is performing in accordance with the specifications that have been specified for it. A verification indicates the likelihood that a measurement error is less than the specified maximum permissible error, if the measurement error is smaller than the maximum permissible error. In a verification, you can specify the maximum permissible error, which is the largest error you are willing to accept as the result of the verification. It is necessary to calibrate the process in order to compensate for any inaccuracies or to apply corrections, as the process does not compensate for these issues.
It is the process of returning a CMM to its original specifications after it has been calibrated. The calibration of your machine is a completely separate service from the verification of your machine, and there are several factors that you should consider when thinking about calibrating your machine.
The accuracy of metrology equipment is critical, so it's important to remember that expanding your tolerance of permissible errors when performing a verification can reduce your ability to maintain control over measurement uncertainty and quality standards. It is critical that you comprehend the services provided by your CMM service provider. We are aware that some service providers refer to 'calibration' as'verification,' when they really mean the opposite. It appears to be more complicated and time-consuming, but in reality, they are frequently unable to adjust your CMM's error map.
Also important to understand is the type of service that will be provided. In addition to routine preventive maintenance, will your CMM receive a thorough service, including fine-tuned adjustments to bring it back into compliance with OEM specifications? Or will they simply issue you a certificate at the end of the process that verifies the machine's permissible error was in fact a mistake? Irrespective of whether the specification has strayed or not?
In addition, it is critical to determine how long it will take your service provider to complete the verification and calibration process on your behalf. The reason we always recommend a two-day visit at Status is that our Length Bars (Gauge Blocks) require soaking time in order to become acclimated to the machine's environment. This soaking time takes a minimum of 24 hours. Because of this, when engineers begin working on a customer's machine, it's common for them to start with this step. It is critical to unpack the gauge block first so that the soak can take place during the first 24 hours while other service-related tasks are being completed in order for the process to take the shortest amount of time possible to complete.
The certification of the service provider is the most important thing to keep in mind throughout this entire process. Is the service provider a nationally recognized calibration laboratory accredited in accordance with ISO 17025 and certified to the ISO 10360 standard for certifying equipment? These levels of accreditation are essential for ensuring the competence of testing and calibration services; they represent the bare minimum of what you should expect from your testing and calibration provider. This is standard procedure for any OEM engineer who wishes to perform a complete calibration, or even a verification of their product.