Right counter height can improve fingerprint capture / EurekAlert!, 19 January 2007
http://www.eurekalert.org/pub_releases/2007-01/nios-rch011907.php
"As part of its role under the USA PATRIOT Act, researchers at the National Institute of Standards and Technology (NIST) conducted a study examining the effect of the work surface height of a fingerprint sensor on the quality and the time required to collect prints."

Effects of Scanner Height on Fingerprint Capture / NIST, December 2006
http://zing.ncsl.nist.gov/biousa/docs/NISTIR-7382-Height%20Study.pdf
Mary Theofanos et al