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Good afternoon, you can use a metal detector these often have very good precision.
Something like the the one here would do the job. Are you just looking to avoid the pipe when drilling?
Thats your best bet I always drill a pilot hole and then use a bit of straight wire 1mm thick eg wire coat hanger to poke through the hole to check there isnt anything there shouldnt be (as its wasy to fill a 1mm hole, and gives you confidence to go full bore.