Satec Expertmeter EM720 Operation Manual page 160

Chapter 9 Viewing Log Files and Reports
Delta Measurements
160
To measure the distance between two trend points, click
on the Delta button
then click on the second point. The first reference point is
still frozen until you close and reopen Delta, while the
second point can be placed anywhere within the trend
line. You can measure a delta in both directions. To
disable delta measurements, click on the Delta button
once again.
EM720 Power Quality and Revenue Meter
Viewing the Data Log
, then click on the first point, and