Official websites use .gov
A
.gov website belongs to an official
government organization in the United States.
Secure .gov websites use HTTPS
A lock (
) or https:// means you've safely
connected to the .gov website. Share sensitive
information only on official, secure websites.
Contact length 
of three seta tips for each position z of the piezo stage. Symbols correspond to different seta types: spatula-shaped (squares), discoidal (circles) and pointed (triangles). Filled symbols represent loading (increasing z), whereas open symbols correspond to unloading (decreasing z).
