horizontal scan rate(HSR) The measure of how many {scan lines} of {pixels} a {monitor} can display in one second, expressed in kHz (generally somewhere between 20 and 100 kHz). The HSR is controlled by the horizontal sync signal generated by the {video controller}, but is limited by the speed with which the monitor can scan the electron beam horizontally across the screen and then return it to the beginning of the next line. (1996-02-09)