NIST discovers ideal height for fingerscanning machines

Published 23 January 2007

Improper installation can lead to slower enrollment times and higher error rates; 26 inches causes better image quality, but 36 inches makes the process go smoother

Biometrics technology can be so fascinating that often integrators and purchasers alike forget that real live human beings actually have to use it. Indeed, the human factor presents one of the largest challenges to iris scanning (let alone the brain scanning approach we reported on last week), and, although few are wary of fingerscanning, the proper installation can mean the difference between success and failure. One often overlooked but critical factor: the height of the scanning machine.

To this end, researchers at the National Institute of Standards and Technology (NIST) recently conducted a study to examine the effect of the work surface height of a fingerprint sensor on the quality and the time required to collect prints. They collected five types of fingerprint images - right and left slaps, individual thumbs, and both thumbs together — from 75 NIST employees. Work surface heights varied from 26 inches to 42 inches, while the fingerprint scanner used in the study added an additional 6 inches (the expected height of the next generation of fingerprint scanners to be used in many federal government applications).

The researchers found that participants performed fastest using a work surface height of 36 inches. However, a height of 26 inches produced the highest image quality. Participants preferred a work surface height of 32 or 36 inches. The 42 inch height was found to be the most uncomfortable. Seventy-six percent of the participants preferred starting with their right hands, which also made the process faster. Quality dropped dramatically when thumbprints were taken simultaneously rather than one at a time.

-read more in this NIST news release; read NIST’s report