adapter supplied with the instrument. The DC power source plugs into the DC
power input on the right side of the 1521.
WARNING: The AC adapter has circuits with high voltages inside that
could present danger of electric shock or fire if exposed. If the AC adapter
is damaged in any way or becomes hot, discontinue its use immediately,
disconnect it from any AC supply, and have it replaced. Do not attempt to
open, repair, or continue using a damaged or defective AC adapter.
6.3 Power Button
The power button controls power to the instrument and operates the backlight.
The following table summarizes the power button functions.
Function Action
Power on Press the power button for at least two seconds when the power is off
Power off Press the power button momentarily (1/2 second or less) when the power is on
Backlight on Press the power button for three seconds or more when the power is on and
the backlight is off
Backlight off Press the power button for three seconds or more when the backlight is on
6.4 Display and Backlight
The display shows measurement data and other information depending on the
selected mode.
The upper part of the display continually shows the most recent measurement.
It uses large digits for easy viewing. A new measurement is produced and dis
-
played every second. The unit associated with the measurement is shown in
21
6 General Operation
Power Button
+
–
Figure 5 12V DC Power Source Polarity
