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.
The differential amplification of height. (A) David’s height is indicated by the red (+) line and Lou’s height is indicated by the black line (−). (B) The height indicators are now depicted as electrode leads with G1 and G2 inputs to the operational amplifier, which sums the two heights as described in panel (A). The resulting output is the height difference. (C) The ground is now introduced to account for an “offset” where the height comparison is made above ground.
