Convert from micron to palmo [Texas]

Unit Definition (micron)
A unit of length. One Micron = 39 millionths of an inch (.000039"). Contaminant size is usually described in microns. Relatively speaking, a grain of salt is about 60 microns and the eye can see particles to about 40 microns. Many hydraulic filters are required to be efficient in capturing a substantial percentage of contaminant particles as small as 5 microns. A micron is also known as a micrometre, and exhibited as µm.

Unit Definition (palmo [Texas])
The palmo is a traditional unit of distance in Spain and Portugal. The traditional Spanish palmo equals 9 pulgadas or 1/4 vara. In Texas, 1/4 vara comes to 8 1/3 inches (21.17 centimeters). These units are based on the width of a person's outstretched hand, from the tip of the thumb to the tip of the little finger, a definition identical to that of the English span.