When performing outdoor plumbing work or other digging projects that may affect pipes underground, it's important to know where the pipes are and aren't. One way to find copper pipes without busting up concrete or accidentally running into pipes while digging through dirt is to use a metal detector. Many metal detectors have settings that allow you to determine what type of metal is being detected. For instance, if you want to find only copper pipes, there's a copper setting that will tune out everything else. Metal detecting can help prevent costly accidents because you'll be sure where the copper pipes lie before proceeding with your project.
Practice using the metal detector to learn the meanings of its various beeps and visual indicators. Place coins of various denominations several feet apart outside, as well as a keychain or other small metal objects. Turn on the detector and wave it gently over one of the coins, noting the tones the detector produces.
Wave the detector coil over the other coins, one at a time, to note the beeps or visual indications given by the detector. Move the detector coil above the keychain or other metal object and note the detector's tones. Continue practicing until you are familiar with operating the detector, consulting the manual when necessary.
Move the detector over ground where you believe the pipes are buried. Search first in areas not covered by concrete for more accurate readings. (See note in Warnings section.) If you aren't hearing any tones from the detector, turn up the detector's sensitivity setting and set it to find just copper. If there is no such setting on your detector, set it to detect all metals.
Continue waving the detector over areas of ground until you find an area that produces signals in a straight line, which would indicate a pipe. Place golf tees in the area of the line, if detecting over dirt, to mark your pipe for future reference. If over concrete, mark the pipe area with chalk.