• Digital multimeter measures current, voltage, resistance, and frequency.
• True RMS (root mean square) meter provides accurate readings when measuring linear or nonlinear loads where the current or voltage has an undistorted or distorted waveform.
• Logic test reports the logic state of an electronic circuit.
• Audible continuity sensor confirms a circuit conducts electricity, and diode test detects proper functioning of a circuit’s diodes.
• Meets International Electrotechnical Commission (IEC) safety standard 61010 and is certified for Category III installations up to 1,000V.

Style:with NIST Certificate The BK Precision 391A digital multimeter (also known as a multitester) is a true RMS, manual-ranging meter for measuring current, voltage, resistance, and frequency in electrical testing applications. The meter comes with a set of detachable test leads. The logic test reports the logic state of an electronic circuit. An audible continuity sensor confirms a circuit conducts electricity, and a diode test detects proper functioning of a circuit’s diodes. The meter measures duty cycles to 90%, indicating the percent of time a circuit is on. The microamp function identifies current changes in flame detector applications. A hold function keeps a reading on the display, even after the meter has been disconnected. An alarm sounds when the test leads are connected to the wrong jack for the measurement being taken. The unit automatically turns off after 45 minutes of nonuse to conserve battery life, and a low-battery indicator signals when the meter's batteries need to be replaced. The meter's body is made of molded rubber, which helps protect it against damage from falls, impacts, and abrasion. The meter has a built-in tilt stand for propping on a flat surface, and a hanging strap is included for hands-free use. This true RMS (root mean square) meter provides accurate readings when measuring linear loads, such as standard induction motors and incandescent lights, where the current or voltage has an undistorted waveform, or nonlinear loads, such as electronic devices or motors, where the current or voltage has a distorted waveform. It is a manual-ranging meter that requires the operator to choose the appropriate operating range for the property being measured. The LCD has a 20,000-count resolution, meaning it can display up to 19,999 units (4-1/2 digits) before the operating range needs to be changed. It meets International Electrotechnical Commission (IEC) safety standard 61010 and is certified for Category III installations up to 1,000V, which covers items used with enclosed building circuit installations (such as service panel parts, branch circuits, and fixed installations that are connected directly to a building's AC power supply). Specifications -------------- Maximum alternating current (AC) input 20 amp Maximum direct current (DC) input 20 amp Maximum AC voltage input 750 volts (V) Maximum DC voltage input 1,000V Maximum resistance detected 20 megaohms Maximum frequency detected 200 kilohertz (kHz) Logic threshold Pass = 2.8, + or – 0.8V; Fail = 0.8, + or – 0.5V Duty cycle measurement range 0 to 90% Power supply 9V battery (one, installed) Standards met European Conformity (CE) marked; Underwriters Laboratory listed; International Electrotechnical Commission (IEC) safety standard 61010-1 Weight 320 g/11.3 oz. Dimensions 198 x 90 x 40 mm/7.8 x 3.5 x 1.57 inches (H x W x D) mm/ H is height, the vertical distance from the lowest to highest point; W is width, the horizontal distance from left to right; D is depth, the horizontal distance from front to back. Multitesters (also called multimeters) are electrical test meters that measure multiple properties of an electrical circuit, such as current, voltage, resistance, capacitance, and continuity. Available in handheld or benchtop models, multitesters diagnose electrical problems in electrical equipment, wiring, and power supplies. A variety of probes, clamps, and leads can be used to connect the meter to a circuit or device. Multitesters display information either in analog or digital form. Factors that influence meter choice include the electrical properties to be measured, the anticipated range of results, and the desired level of protection against transient voltages. Safety ratings are based on the International Electrotechnical Commission's (IEC) standards for low-voltage test equipment. IEC 61010 delineates four overvoltage installation categories. In general, a meter with a category IV rating will provide more protection against transient voltages than a meter with a lower category rating. BK Precision manufactures test and measurement instruments for research and development, production-line testing, and electronic field service applications. The company, founded in 1951, is headquartered in Yorba Linda, CA. It meets International Organization for Standardization (ISO) standard 9001:2008 and is compliant with Restriction of Hazardous Substances (RoHS) and waste electronic and electrical equipment (WEEE) directives. What's in the Box? ------------------ * BK Precision 391A true RMS digital multimeter * (1) Set test leads * 9V battery (installed) * Spare fuse * Hanging strap * Instructions