Holiday detectors are devices used to minimise the effects of corrosion by detecting the presence of ‘holidays’ or defects in non-conductive coatings by creating a voltage potential on an electrode, passed over a conductive surface. The detector is also grounded so 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.
When a holiday detector’s voltage output seems affected by weather conditions, moisture on the pipe, improper grounding or soil conditions during inspections, the SPY Model JM provides a digital display of measured voltages eliminating interpretation errors during the troubleshooting of holiday detector operations.
In addition, the SPY Model JM Jeepmeter’s solid-state electronics ensure stability and repeatability. The Jeepmeter verifies the accuracy of the holiday detector by providing a highly accurate measurement of both pulse and direct current (DC) voltage. For thin film and epoxy coatings, the JM can also measure from 0–5 kV in its DC range. For pulse type holiday detectors that inspect shrink sleeves, tapes, coal tars and other thick coatings, the JM measures up to 40 kV.
Pipeline Inspection Company also offers two pocket-sized Jeepmeters for ‘on spread’ quick reference checks. Model DCJPM, for thin coating DC holiday detectors, measures in the 0–5 kV range, while the Model PJM is used for high voltage pulse output detectors that inspect thick coatings with a range of 0–20 kV.
Article continues below…While the pocket Jeepmeters are not comparable to the accuracy of the larger, more versatile Model JM Jeepmeter, they are capable of meeting field requirements combining durability, reliability and sensitivity. With their economical cost and convenient size, these pocket Jeepmeters are ideal for everyday field use.
