3M 2250E, 2273E Determining Cable Depth and Current, Using Current Indications During Locating

DETERMINING CABLE DEPTH AND CURRENT

Place the Receiver Antenna on the ground directly above the cable with

the handle parallel to the path. Press and the display will indicate

the cable depth and relative current . Current is displayed in the lower

left corner of the display. Press twice to continue tracing. You may

also press to return to Trace mode.

Note: During a depth-current measurement, the display will exhibit ' – – – ' when the received signal is too low, too high, or erratic.

Using Current Indications During Locating

Both the Transmitter and Receiver will indicate cable current. These current indications will help to select a trace frequency, identify the correct cable and trouble shoot the set up.

When using the direct connect method, the Transmitter output current number is displayed. A "LO" display, or number less than 50, indicates a weak tracing signal. A number higher than 70 represents a strong tracing signal. When the Receiver is used to find the cable near the Transmitter connection point, the current number displayed in the Receiver should correspond (within 5 points) to the Transmitter number: IF you are over the correct cable, AND most of the signal is flowing in that cable.

Note: On the Transmitter every ten units on the current display represents a factor of two in current magnitude. On the Receiver, trace current readings for the additional auxiliary frequencies (except LF) are displayed in milliamps. For all other trace frequencies every ten units on the Current display represents a factor of two in current magnitude.

When the Transmitter signal is applied using the Dyna-Coupler, the Transmitter current display indicates the current in the coupler and not in the cable. In order to get a measure of the cable current, point the Receiver at the exposed cable about one meter from the Dyna-Coupler. This will be the current number that should be used to identify the correct cable.

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