The Fluke 381 digital clamp-meter is a true RMS sensing, auto-ranging multimeter for measuring current, voltage, frequency, and resistance in electrical testing applications. It has a clamp that measures AC (alternating current) to 1,000A (amperes) and comes with a flexible probe that measures AC to 2,500A. Frequency to 500Hz (hertz) can be measured with the clamp or probe. The clamp has two jaws that can close around an electrical conductor up to 34mm (1.3 inches) in diameter and the flexible probe has an 18-inch circumference to measure current without touching or interrupting the circuit. The probe improves access to wires and enables measurement of large and irregular-sized conductors. A set of test leads is included for measuring AC and DC voltage to 1,000V and resistance to 60kΩ (kilohms). The meter has a rotary switch to select the property to measure, and an LCD with a backlight for visibility in low light that turns off automatically after two minutes. The display can be removed from the meter's body and has an integrated wireless transmitter for positioning up to 30 feet away from the point of measurement for remote readings. Its magnetic backing allows for convenient remote positioning and subsequent reattachment to the meter.
The meter's inrush current function analyzes the surge current at the startup of motors and other inductive loads to provide accurate, stable measurements. It features a low-pass filter that reduces high-frequency interference to allow accurate measurements of complex wave shapes. The minimum/maximum/average function toggles to display the lowest, highest, and average readings for a property. To aid documentation of readings and capture readings in tight spaces, the data hold function keeps the reading on the display after disconnecting from the circuit. A continuity buzzer confirms that the circuit conducts electricity. The unit operates on five 1.5V AA batteries, and turns off automatically after 20 minutes of non-use to conserve battery life. It has a low-battery indicator that signals when the battery needs to be replaced.
This true RMS (root mean square) sensing meter provides accurate readings when measuring linear or non-linear loads, regardless of the waveform. It is auto-ranging, so it automatically selects the appropriate operating range for the property being measured. Accuracy and resolution specifications vary according to the range being measured. The meter meets EN (European Standards) and IEC (International Electrotechnical Commission) safety standards 61010-1:2001 and is rated for CAT (category) IV installations up 600V, which covers equipment at the origin of the installation, such as electricity meters and primary over-current protection equipment, and CAT III installations to 1,000V, which covers equipment in fixed installations, such as switches in the fixed installation and some industrial equipment that is permanently connected to the fixed installation. It is certified by TÜV (Technischer Überwachungs-Verein), and complies with CSA (Canadian Standards Association), and Australia N10140. The unit comes with a soft carrying case.
|Maximum AC (alternating current) input||1,000A via clamp; 2,500A via flexible probe|
|Maximum DC input||1,000A|
|Maximum AC voltage input||1,000V|
|Maximum DC voltage input||1,000V|
|Maximum frequency detected||500Hz|
|Maximum resistance detected||60kΩ|
|Installation rating||CAT IV, 600V|
|Standards met||EN and IEC safety standard 61010-1:2001; CE marking; TÜV (Technischer Überwachungs-Verein); CSA; Australia N10140|
|Power supply ||(5) 1.5V AA alkaline batteries|
|Dimensions (H x W x D)||277 x 88 x 43mm/10.905 x 3.464 x 1.629 inches |
H is height, the vertical distance from lowest to highest point; W is width, the horizontal distance from left to right; D is depth, the horizontal distance from front to back.
Clamp-meters, also called clamp-on meters, have two jaws that fit around a conductor to measure electrical current without cutting through wires, or touching or interrupting the electrical circuit. Available in handheld or benchtop models, clamp-meters diagnose problems in electrical equipment, wiring, and power supplies. All clamp-meters test for current. Some come with test leads and inputs for measuring voltage, capacitance, and resistance. They 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.
Fluke Corporation manufactures electrical testing tools and software for industrial and commercial applications. The company, founded in 1948, is headquartered in Everett, WA.
What's in the Box?
- Fluke 381 digital clamp-meter
- 18-inch flexible current probe
- Test lead set
- (5) AA batteries
- Soft carrying case