Holiday Detectors are devices used to minimize the effects of corrosion by detecting the presence of "holidays" or "defects" in non-conductive coatings.

They detect defects by creating a voltage potential on an electrode, passed over a conductive surface. The detector is also grounded. As holes or fissures in the coating are passed over, the voltage jumps the gap and completes a circuit which then causes a horn (also known as a jeep) to sound.

Pig Trackers are devices that are used to track 
the passage and locate a pipeline pig that is equipped with an appropriate transmitter. These devices enable operating and maintenance companies to minimize the costs involved with excavating and removing stuck pigs.