Cable Locating Depth and Current Readings
• The RD8200 locator provides automatic depth readings for buried cables, pipes, and sondes when oriented correctly above the target line or sonde.
• Depth measurement is to the center of the pipe, cable, or sonde, with best readings typically from active signals output by a transmitter.
• Depth readings may not be accurate if there is audible interference or if part of the transmitter signal has coupled to a nearby line.
• To accurately pinpoint the target line with the locator, check the locator is directly over the line, the antennas are at right angles to it, and the locator is vertical. Adjust the sensitivity level to bring the bar graph indication to approximately 50%.
• To verify depth measurements, lift the locator 50mm above the ground and repeat the measurement. If the measured depth increases by the same amount, it is a good indication that the depth reading is correct.
• To check depth accuracy, check that the depth reading on the locator when used for markers or conductors and sondes is within acceptable limits.
• There are two ways of checking the calibration of the locator in the field: placing the transmitter on top of a non-metallic object, or applying a signal to a cable or pipe of known depth.
• Current readings help confirm the identity of a line and may provide information about the condition of cable insulation or pipe coating.