The Model 670 is lightweight and easy to handle. The electrode wand assembly is easily inserted into the unit and secured.
Since the working voltage is quite low, a direct connection from the ground cable to the conductive metal under the coating must be made. A trailing ground wire will not suffice.
Inspect more area faster. A revolutionary roller sponge electrode is an optional accessory for the Model 670. With this roller sponge electrode, coating inspections move along faster and with less operator fatigue.
The Model 670 operates on a single 9 volt alkaline battery housed in the detector handle. These standard batteries are readily available at retail stores. Under normal conditions, the battery will have a long life. There is a minimal drain on the battery until a holiday is discovered. Unit output is 67 volts DC. This voltage makes this detector sensitive and accurate. A uniform coating of only one mil of paint or other non-conductive material is sufficient to repel this small current. If a pin-hole holiday is encountered, moisture from the sponge will seep in to create a free path for electrical flow, activating the signal horn.
For coatings from 1 mil up to 10 mils thick, ordinary tap water can be used to wet the sponge. Above 10 mils, for coatings of 11 to 20 mils thickness, a non-sudsing wetting agent (such as Kodak Photo-flow R®) is recommended to increase the ability of the moisture to swiftly make its way through pin-holes in the thicker coating.