Current or voltage detectors are employed to measure or test current strength of electronic components or to localize electrical lines. Devices with similar or same functions like phase testers, voltage detectors, continuity testers or multimeter check, whether electrical power is applied to a line or a cable break occurred. Furthermore, they can check the amount of voltage power of a certain line or which one is the live braid.
The Alpha and Omega: the CAT-measurement categories
Before using current or voltage testers its CAT-measurement categorie should necessarily be heeded. According to IEC-61010, these categories divide the power supply system into four different overvoltage categories, CAT I up to CAT IV, and into three voltage levels 300V, 600V and 1000V. For example, batteries and battery operated devices belong to the lowest categorie CATI. Devices working close to the power source like electricity meters or the electric main connection belong to the highest category CATIV.
The voltage classification’s principle is the following: The higher the voltage range is within one category, the higher its resilience resp. attenuation capability to voltage peaks like a lightning. The current tester’s proper measurement category is crucial in order to prevent accidents, that could occur, if multimeter are used for voltages that are too high.
If a suitable testing device for the greatest possible application has been found, obviously all applied lines and cables shall necessarily meet the categories as well – otherwise even the best current tester is needless.