Starrett Chordal Height Gage measures opening heights of turbine vanes to verify aircraft engine air flow

The L.S. Starrett Co. has introduced a custom designed and manufactured Chordal Height Gage (DO Gage) to be used for measuring the opening heights of turbine vanes at specific locations to verify that an aircraft engine will get proper air flow. The new gage is part of the Starrett line of special area flow gages.

The size is determined based on the specific application it will be used on, and the new gage is no larger than a tissue box. Despite the small footprint of the gage, it has three independent probes which are used to take measurements, including a free-floating central gage body, which allows the middle probe to take accurate readings along the trailing edge, regardless of the variable contours which are often on these nozzles.

The gage is built in a “Lazy-L” shape to enable linear readings to be taken perpendicular to the trailing edge of the blades, giving a dimension for the smallest opening that air can flow through. These features help contribute to the accuracy and repeatability of the gage, which is within 0.0005 in., although the indicator readouts are generally set to a 0.001 in. resolution per customer requirements.

The L.S. Starrett Company | www.starrett.com