3M 2273E - Manual (Page 17)

LOCATING AN ACTIVE DUCT PROBE (ADP)
Press to turn the Receiver on.
Press to select the 33 kHz frequency.
Press to select the Peak mode . If you find that the received
signal is too weak in this mode, try the Special Peak mode. To select
Special Peak mode: from Peak mode, press and hold , then press
to toggle between Peak and Special Peak modes. While in Special
Peak mode, the Peak flag will flash.
With the Receiver handle perpendicular to the conduit path, locate the
ADP position by moving along the path until a peak is found. Press
when the bar graph remains either fully open or fully closed. Refer to the
ADP operating instructions for further information.
Determining ADP Depth
Place the Receiver Antenna on the ground directly above the located ADP
position maintaining the handle orientation perpendicular to the path.
Press twice to display ADP depth .
To return to trace mode, press or .
Note: During a depth-current measurement, the display will exhibit
' – – – ' when the received signal is too low, too high, or erratic.
Page 16