In this line of work, the question overseas buyers ask most often is not about accuracy. It is whether the device will still be doing its job after a few years bolted to a pole or sitting inside a cabinet, exposed to weather. IP, EMC, and salt spray are basically the answer to that question. They are not there to fill up a parameter table. They tell the customer what conditions we qualified the product against, and whether those conditions match the site.
The source of the IP code is the IEC 60529. It is made of two digits: the first one relates to solids; the second has to do with liquids. IP65 is the minimum rating that a wireless locator uses outdoors; there shouldn't be enough dust to interfere with the operation of the device, and water jets from any direction will not harm it. The addition of IP67 will imply short immersion of 1 meter for 30 minutes, which is vital for the regions that are subject to flooding or accumulation of rainwater. The only thing we explain to our clients is that the IP ratings cannot be summed up. Passing an immersion test does not mean the unit survives a directed jet. The two tests stress the seals differently-static pressure versus moving water. If the site has both, ask for both ratings and the matching reports.
EMC, put simply, is whether the device can hold its measurement and avoid resetting in the electromagnetic environment of a distribution network. The locator connects to current transformers and communication ports, so noise comes in both through cables and through the air. We focus on four tests. IEC 61000-4-2 is electrostatic discharge. Level 4 requires 8 kV contact and 15 kV air discharge, with no permanent damage and no loss of function. Opening a cabinet in dry weather, or nearby equipment discharging into a grounded frame, is exactly this scenario. IEC 61000-4-3 is radiated radio-frequency fields. 10 V/m from 80 MHz to 1 GHz, now usually extended into higher bands, checks whether the device still measures when someone nearby is using a handheld radio or a base station is transmitting. IEC 61000-4-5 is surge, with a 1.2/50 µs open-circuit voltage and 8/20 µs short-circuit current waveform. On distribution lines, 2 kV or 4 kV is not a paper number-it is energy coupled from switching operations or distant lightning. IEC 61000-4-4 is fast transient bursts, typically 1 kV on power ports and 0.5 kV on signal and control ports, corresponding to what couples into communication wiring.
Salt spray testing is usually the most requested by coastal and industrial customers. IEC 60068-2-52 is one of the standards for testing cyclic corrosion. What really matters in this case is the severity and the methodology used. Just saying "passed salt spray testing" doesn't tell you much on its own. Severity levels 1 and 2 are meant for marine and near-marine atmosphere. The 1st method states that 1 cycle of salt spray testing takes 2 hours at 35 degrees C and then a humid storage. This cycle is done four times for 28 days. At the same time, the 2nd method has less cycles and lesser duration but the method is still the same: the housing, terminals, and exposed metal parts are repeatedly salted, dried and salted.
When overseas customers compare locators from several suppliers, especially for overhead line or coastal sites, these three test families should be read together. An IP65 or IP67 line is only the starting point. The EMC levels show how much electrical hostility the unit was qualified to ride through. The salt spray method and duration show whether the corrosion claim rests on a defined test. As a supplier, we would rather put the standard number, the level, and the report reference on the table. It lets customers compare with the same ruler, which is more useful than a pile of adjectives, and it gives a rough idea of what the device will look like after a few years in the field.
