Phase meters (phase testers, phase rotation meters) check the phase sequence and phase orientation in three-phase electrical systems. They are used for energy measurements, and the monitor the quality of audio and video transmissions. Correct phase matching is also important in energy metering applications since phase mismatches between channels may cause significant measurement errors at low power factors. Bandwidth, sampling rate, maximum channels, and operating temperature are important parameters to specify when selecting phase meters. Bandwidth is the frequency range over which current or voltage is measured. Sampling rate is the frequency that a digital meter tests an analog signal and converts to a digital value.
General specifications for phase meters, phase testers and phase rotation meters include display type and form factor. There are two choices for display type: analog and digital. Form factors are listed as bench or free-standing, clamp meter, rack-mounted, handheld, or computer compounds. Benchtop phase meters are designed to sit atop a bench or table; or are free-standing units with a full casing, cabinet, and integral interface. Phase meters that function as clamp meters can measure current through wires that are still connected to a live circuit. Rack-mounted electrical test equipment is designed for mounting in telecommunications racks and includes hardware such as rail guides, flanges and tabs. Handheld devices are designed for use while held in one hand. Phase meters with a computer-board form factor are printed circuit boards (PCBs) that plug into computer backplanes or motherboards.
Phase meters, phase testers and phase rotation meters may bear quality marks and comply with national or international standards for safety and performance. The CE Mark indicates that product complies with the relevant European Union (EU) directives and upholds recognized standards for health, safety, and environmental protection. These standards include the requirements defined in the EU’s Restriction of Hazardous Substances (RoHS) and Waste Electrical and Electronics Equipment (WEEE) directives. Phase meters that bear a CSA Mark have been tested by the Canadian Standards Association (CSA) and meet applicable standards from organizations such as Underwriters Laboratories (UL). Recognized standards for safety and performance also include IEC 61010 from the International Electrotechnical Commission (IEC).