Maintaining a Tight Tolerance for Heat Flux Gauge Masks


In the aerospace industry, instrumentation is an important point of concern. Researchers are constantly searching for ways to design precise, reliable instruments that deliver accurate measurements.

One instrument that falls under this umbrella is the heat flux gauge. While applicable to a variety of aerospace applications, the Gas Turbine Lab at The Ohio State University Aerospace Research Center uses these gauges to measure temperature and heat flux on a rotating turbine rig.

Designing Masks for High-Density Heat Flux Gauges

At one point, The Ohio State University had made their own heat flux gauges in house. More recently, however, the manufacturing of these gauges has been outsourced, and part of that design process includes creating masks for them.

The easiest way to think about these masks are as stencils you would use for spray painting. As a sheet of Kapton is sandwiched between two masks, metal is critically heated and the free particles move to form a shape outlined by the stencil — the actual gauge.

Because the gauges are double-sided, their design needs to be very precise to ensure alignment. In addition to this tight tolerance, the gauges themselves are also incredibly small and thin.

To meet these requirements, the researchers turned to Switzer as their manufacturer.

Switzer Delivers Tight Tolerance for Aerospace Design

As part of the project, the team at Switzer manufactured two different types of heat flux gauge masks. And for each of these designs, both a front and back mask were produced.

Because the masks were so small, laser cutting was out of the question. Instead, chemical etching was used to achieve the very tight tolerance required by the application.

In addition to these masks being extremely small, part of the quality control also related back to lining up the gauges properly. The goal was to essentially sandwich the masks together so the only element seen front to back is a tiny serpentine passage.

As Richard Celestina, a graduate research associate in the Gas Turbine Lab, notes, Switzer was able to handle this part of quality control as well. “The fact that Switzer was able to keep a tight tolerance and allow for the alignments of these serpentine passages was very impressive,” he said.

Have an idea for a metal part or a design that’s ready? In either case, Switzer can help bring your part to life while ensuring customer satisfaction. Contact us to learn more about how we can help with your project.




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