Heath Consultants Sure-Lock All Pro - Manual (Page 33)

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These results may also indicate that the operator should reposition the transmit-
ter or go to a different transmitter mode of operation to energize the conductor.
Factors Affecting Depth Readings
1. Interfering conductors in the area.
2. Type and conductivity of soil.
3. Receiver not centered on target.
4. Depth of burial versus size of target.
5.
depth readings.
6. Changing conductor depth or a tilted conductor at the reading location.
7. Frequency selection (lower frequencies preferred).
8. Grounding method.
The above factors should always be taken into consideration when taking a
calculated depth reading with the receiver. If not, calculated depth may have
inaccuracies greater than 20% of the actual value.
**NOTE**
THIS CONDITION MAY BE EVALUATED USING TWO METHODS. ONE
METHOD IS BY PIVOTING THE RECEIVER 180 DEGREES WHICH MAY
PRODUCE DEPTH READING WHICH DIFFER BY
10%. SUCH DIFFERENCES UP TO 15-20% MAY BE AVERAGED AND
WHICH CAN BE THE RESULT OF A TILTED CONDUCTOR WHICH
OCCURS NATURALLY WHERE A FORWARD OR RE- VERSE GRADE
EXISTS. DIFFERENCES GREATER THAN 20% INDICATE INACCURATE
DEPTH READINGS. A SECOND METHOD IS SOMETIMES CALLED
THE “LIFT TEST” AND IN- VOLVES TAKING A STANDARD CALCU-
LATED DEPTH READ- ING AND THEN LIFTING THE RECEIVER UP
A KNOWN DIS- TANCE AND OBSERVING THE NEW CALCULATED
DEPTH READING ON THE DISPLAY. THE UPDATED CALCULATED
DEPTH READING SHOULD INCREASE BY THE DISTANCE THAT THE
RECEIVER WAS RAISED. PIVOTING THE RECEIVER MAY ALSO BE
USED WITH THE LIFT TEST.