Safety 1st Advancer Návod k obsluze stáhnout pdf (Strana 24)

Environmental Remediation Drilling

Safety Guideline

Page 24 of 132

2.6.4 - Deep Focused Sensing Metal Detector

A deep focused metal detector acts as a pipe and cable locator and tracer to detect and trace metallic

utilities, utility tracing wires, or warning tapes. In pipe and cable search mode, the instrument is essentially a

deep-sensing metal detector that detects any highly electrically conductive material (metals) by creating an

electromagnetic field with a transmitting coil. A receiving coil at a fixed separation from the transmitter

measures the field strength. As the instrument is swept along the ground surface, subsurface metallic bodies

distort the transmitted field. The change in field strength or orientation is sensed by the receiver and triggers

an audible alarm and deflection of an analog meter. The instrument can nominally detect a 2-inch metal pipe

to a depth of 8 feet and a 10-inch metal pipe to a depth of 14 feet.

Figure 2.4 - A Deep Focused Metal Detector Being Demonstrated in a Non-environmental

Remediation Work Area. (Photo courtesy of Enviroscan, Inc.)

This technique’s effectiveness is limited to metallic objects. It is not useful for plastic, ceramic, or fiberglass

utilities.

2.6.5 - Vibrocator

Vibrocators are used to detect and trace fluid-filled, non-metallic utilities (for example, PVC or concrete

water lines). A vibrocator system involves a low-frequency pressure wave generator (called a transonde),

which is attached to a faucet, hydrant, or other available fitting. The transonde produces a continuous

vibration or throbbing in the pipe. This vibration can be detected at the ground surface with a sensitive

geophone or ground motion detector tuned to the transonde-generated frequency.

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Safety 1st Advancer Návod k obsluze Strana 24