What is calibration and why is it a “good thing”?

18 September 2017

What is calibration and why is it a “good thing”?

Recently, we at Thor3D, decided to add a calibration kit to every Drake scanner we ship. But what is “calibration” and how will it benefit our customers?

Every 3D scanner including “laser”, “white light”, “structured light”, “probe”, “arm” or “terrestrial”, needs calibration. This is a process by which a scanner’s software is adjusted to its hardware using a standard scale. This is usually done with the help of a large board full of dots (or other symbols) and software written specifically by mathematicians for this purpose. Some scanners are calibrated once at the factory, while other manufacturers encourage their users to calibrate before every scan job and provide the necessary tools. Until recently, the Drake scanner fell into the first category: calibration was done once on the factory floor. This was convenient for the client and the manufacturer, but the more time went on, the more we started leaning toward the other option: client calibration.

Why did we change our minds?

There are several reasons why we decided to provide a complementary calibration kit with every Drake scanner. 1) Frequent calibration ensures high accuracy for every scan. 2) Significant reduction in repair bills for both manufacturer and client. 3) Company-wide strategic shift toward industrial applications. Let’s discuss each point separately.

Calibration = high accuracy

Most 3D scanner manufacturers advertise their accuracy as “up to ___ mm/in”. This means that your scanner can achieve accuracy of 30 microns, or the same device can attain accuracies of no more than 300 microns. Although many factors play a role in how precise your scanner is, one key factor is calibration. Regardless of how stable factory calibration is, over time, it will decay and your 3D results will degrade. Dust, temperature fluctuations, slight shaking of the device when you set it down on a table, can all cause factory calibration to worsen. Experienced engineers appreciate having a calibration kit to ensure that the last scan, even years after the device was purchased, is still as good as the first.

Reducing the repair bill

We get asked all the time – what is the number one reason for repairs of your 3D scanners? The answer is – lost or degraded calibration. And the most frequent reason for that is: scanners are dropped or handled roughly. And although it doesn’t happen often (maybe 1 in 100), sometimes new scanners even arrive de-calibrated because they were mishandled by the shipping company.

A 3D scanner is highly sophisticated optical equipment and should be handled with great care. However, that is not always possible and even the most cautious users will see their results worsen over time, because of calibration decay.

It is now abundantly evident that by introducing the kit and including it with every Drake scanner, we will be saving tens of thousands of dollars on shipping costs and loss of productivity while the device is out for unnecessary repairs.

Focus on industrial applications

Both the Thor3D and Drake scanners are great at scanning humans. A noticeable portion of our clients are those using their scanners to capture various parts of the human body for various purposes (medicine, research, computer graphics, etc). However, as a company, we have shifted our focus last year to more industrial applications like reverse engineering and quality control. We introduced “scanning by markers” to ensure repeatability and accuracy, as well as released Drake which enables an engineer to scan objects of any size. Adding a calibration kit is a major step as well because without it, we could not guarantee accuracy which is a must in heavy industries such as automotive and aviation.

In conclusion

You might never use your calibration kit, because the factory one will be stable and you’ll handle your scanner with care. But isn’t it nice to know that if you need it, the kit will be there? And if you do need a guarantee of high accuracy for every scan, then use this tool daily and sleep well at night.

Peter & Greg

Thor3D Technical Support Team

THOR3D© 2017