Quality Innovations: Mobile Metrology
April 28, 2009
NanoFocus Inc. (Glen Allen, VA) offers high-resolution measurement on wheels with its µsurf mobile surface metrology system.
The system was developed for customers who wanted to measure the surface topography of work rolls in the steel mills, says Christian M. Wichern, executive vice president of NanoFocus. Doing very high-resolution measurements on large parts was difficult, and there was no equipment to do it. In the case of the steel mills it was impractical to put a microscope on top of the work, and cutting out a piece of the roll destroyed an expensive piece of capital equipment.
The µsurf mobile is a sensor used for measurement of surface heights that is based on the principal of LED confocal microscopy. It provides high-accuracy surface height data and topography, and works well for those manufacturing large but high-precision pieces of equipment, says Wichern. It is not limited to steel industry applications, as it can be used for aircraft and automotive to printing and medical, both in the field and on the shop floor.
The battery-operated electronics and rolling container allow operation in remote locations without external power sources. The unit is ready to measure in about 1 minute, and measurement takes about 5 to 10 seconds. The µsoft software handles the data acquisition and analysis.
Customers do have other resources available for surface measurements, though they differ from the µsurf. Interferometers are one option-they are fairly robust and able to handle high-resolution measurements. However, they also are sensitive to vibrations, which can be a problem in tough industrial environments, Wichern says.
The mobile system, meanwhile, is insensitive to vibrations and offers 3-D measurements.
Contact systems are another option, but these drag a needle across the surface and provide measurements in 2-D instead of 3-D. “That alone has more or less pushed a large part of the surface metrology market toward us,” says Wichern.
Because 3-D engineered surfaces are present in many situations, the product has an advantage, as the optical noncontact system does not damage the surface it is measuring. Mirror surface finishes can be ruined if a stylus is run across them.
This functionality comes at a price, however. Those systems are much lower in price, while the NanoFocus system is a $100,000 investment. In addition, Wichern says customers have historically been using those 2-D systems, and they are entrenched in the market. If a customer has been using those systems for 50 years, he may be reluctant to change, fearing that he will lose old data or the ability to compare systems.
However, the µsurf also can give 2-D data that matches older systems. The challenge is convincing the market of the benefits of 3-D.
Luckily, surface metrology is something that applies to many different applications.
“You would be very hard-pressed to find a product that doesn’t have some sort of critical surface,” Wichern says, and these surfaces’ topography and finish often need to be measured.
Surfaces usually have some requirements, whether they need to be absorbent, as with paper and ink, or anti-glare. If a customer wants to determine why paint is not sticking to a surface, for example, the portable machine can be brought to the shop floor to look at it. The product also can be used on painted or stainless steel that needs to be tested.
“At some point in its life, any manufactured product with a surface that plays an integral role in the product’s performance has been looked at by our machine or one of our competitors,” says Wichern.
After a customer request, the mobile product was developed in Germany during a six-month period. The company invests a lot into research and development-of the 20 people at the German office at that time, at least 15 were part of R&D, Wichern says. The company now has more than 50 employees worldwide, but continues to focus on R&D.
After the first customer prototype was delivered, the company worked closely with its customers to integrate their suggestions into the system. The company welcomes customer feedback and tries to address improvements or issues immediately in order to create the best possible product.
“In Germany, there are already a lot of updates going into the current system,” Wichern says. “It’s a never-ending process.”
Technology ContactFor more information about the µsurf mobile, contact:
4470 Cox Rd., Suite 250, Glen Allen, VA 23060