• Manual-ranging digital multimeter measures voltage, current, capacitance, frequency, and resistance, and performs logic and diode tests.
• True RMS meter provides accurate readings when measuring linear or nonlinear loads where the current or voltage has a sinusoidal or nonsinusoidal 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 IEC safety standard 61010 and is certified for Category III installations up to 1000V.

The B&K Precision 391A digital multimeter (also known as a multitester) is a true RMS, manual-ranging meter used in electrical testing applications to measure current, voltage, resistance, and frequency, and perform logic and diode tests. 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. The kit includes a silicone 4mm sheathed straight-to-right-angle plug lead set, a red and black flexible pincer set, a probe body set with 2mm/0.080" diameter tips, a red and black miniature spring-tip probe, a trifold nylon pouch, and instructions. 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 1000V, 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 10 amp continuous, 20 amps for up to 30 seconds Maximum direct current (DC) input 10 amp continuous, 20 amp for up to 30 seconds Maximum AC voltage input 750V Maximum DC voltage input 1000V Maximum resistance detected 20 megaohms Maximum frequency 200kHz Other tests Diode and logic Power supply 9V battery (one, installed) Safety ratings European Conformity (CE); Underwriter's Laboratory (UL); International Electrotechnical Commission (IEC) safety standard 61010 and is certified for Category III installations up to 1000V Weight 12oz./353g Dimensions 6.88 x 3.5 x 1.5 inches/175 x 89 x 38mm (H x W x D) 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. 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, multimeters 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. Multimeters 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 voltage. Safety ratings are based on International Electrotechnical Commission (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. B&K 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? ------------------ * B&K Precision 391A true RMS digital multimeter * 9V battery (installed) * Spare fuse * Silicone 4mm sheathed straight-to-right-angle plug lead set (1.5m) * Flexible pincer set (red and black) * Probe body set with 2mm/0.080" diameter tips * Miniature spring-tip probe (red and black) * Trifold nylon pouch * Instructions