15
Measuring sonde depth
Pinpoint the sonde as previously described. Then rest the Loki receiver on the
ground with the blade’s orientation parallel to the orientation of the sonde. Adjust
the sensitivity to give a meter reading of 60% to 80% on the LCD’s bar graph.
Note that the depth reading is the distance from the bottom of the locator blade to
the centre of the sonde and not to the drain or duct being located.
CAUTION: Ensure Depth readings are taken from peak readings.
Depth readings taken from ghost signal position will be incorrect.
Depth measurement is automatic. Depth reading will be displayed when the locator
is moved slowly across the sonde. The shallowest depth reading displayed on the
LCD is also the correct position directly above the sonde.
If the signal is too weak or unstable the Loki receiver will not calculate depth. In this
case use a more powerful sonde or use the Pinpoint procedure described below.
Pinpoint Procedure
1. Move the locator ahead of the sonde, ensuring the blade’s orientation is
parallel with the sonde’s orientation.
2. Increase the sensitivity slightly to find the ghost signal. Note that between the
main peak and ghost there is a Null or minimum.
3. Mark the Null or minimum position for reference.
4. Move behind the sonde and repeat step 1.
5. Find the Null between the ghost and main peak. See points A and B on the
diagram on the previous page.
6. The higher the sensitivity of the Loki receiver the sharper the Null’s appear.
