GE Medical Systems MAC 1200 Operator's Manual page 83

Revision B
Recording in 12 Lead Mode: Adjusting Measurement Points/QT Dispersion
On this display you will see all 12 ECG leads; the active lead is black and
displayed in the foreground, the inactive leads appear dimmed in the
background.
The active measurement point marker is large, the four inactive markers
are small. Use these keys to adjust the markers.
moves the active marker right or left
selects the next or previous marker
activates the next lead
lead
changes the gain
terminates the adjustment, saving the changes
terminates the adjustment without saving the changes
space bar for the P onset and P offset values, the space bar toggles
between definite value and approximate value.
MAC 1200
2012250-022
5-23