Fluke Corporation

Jeffrey E Worones

Ronald Steuer

Ricardo Rodriguez

David Lawrence Epperson

Ginger M Woo

Terry G Morey

Christopher D Corrigan

Brian Stanley Aikins

Paul Andrew Ringsrud

Christian Karl Schmitzer

Peter Radda

Patrick Scott Hunter

Ferdinand Y Laurino

Michael F Gallavan

Clark N Huber

Yinzi Liang

Chris Corrigan

Clamp meter

Systems and methods provide a non-contact current measurement system which operates to measure alternating current flowing through an insulated wire without requiring galvanic contact with the insulated wire. The measurement system may include a magnetic field sensor that is selectively positionable proximate an insulated wire under test. In operation the magnetic field sensor detects a magnetic field generated by the current flowing in the insulated wire. Using an adjustable clamp assembly, the measurement system provides control over the mechanical positioning of the insulated wire relative to the magnetic field sensor to ensure consistent measurements. The non-contact current measurement system may determine information relating to the physical dimensions (e.g., diameter) of the insulated wire. Using the detected magnetic field, the known mechanical positioning, and the determined information relating to the physical dimensions of the insulated wire, the measurement system accurately determines the magnitude of the current flowing through the insulated wire without galvanic contact.

Non-contact current measurement system

Systems and methods are provided for measuring electrical parameters in a conductor without requiring a galvanic connection. A device includes a body and a clamp jaw assembly movable between an open position that allows a conductor to be moved into a measurement area, and a closed position that secures the conductor within the measurement area. The clamp jaw assembly includes sensors positioned inside a clamp jaw of the clamp jaw assembly. A user may apply a force to an actuator to move the clamp jaw assembly from the closed position into the open position so that the conductor may be positioned and secured in the measurement area. The clamp jaw assembly includes a visual indicator to guide the user to position the conductor within an optimal region in the measurement area. The clamp jaw assembly is sized and dimensioned to automatically position the conductor within the optimal region during measurements.

Non-contact electrical parameter measurement device with clamp jaw assembly

Systems and methods are provided for measuring electrical parameters in an insulated conductor without requiring a galvanic connection. A sensor probe is provided that includes a body and a flexible arm or strap that is movable between an open position that allows a conductor to be moved into and out of a measurement area of the probe, and a closed position that secures the insulated conductor within the measurement area so that one or more measurements may be obtained. The electrical parameter sensor probe may include a non-contact sensor coupled to at least one of the body or the flexible arm. A user may apply a force to an actuator (e.g., slide switch) which moves the flexible arm from the closed position into the open position against a bias force so that the insulated conductor under test may be positioned and secured in the measurement area of the sensor probe.

Flexible jaw probe for non-contact electrical parameter measurement

Systems and methods for measuring electrical parameters (e.g., voltage, current, power) in an insulated or blank uninsulated conductor (e.g., insulated wire) without requiring a galvanic connection between the conductor and a clamp probe. A clamp probe may include a normally closed, spring loaded jaw having a flexible strap therein that includes one or more non-contact sensors. The jaw may also include a Rogowski coil to enable non-contact current measurements. A user may compress handles of the clamp probe to open its jaw. In the open position, the user may position the jaw around the conductor under test and release the handles. The jaw then closes and tightens the flexible strap around the insulated conductor such that the one or more non-contact sensors are positioned adjacent the insulated conductor to obtain an accurate measurement of an electrical parameter of the insulated conductor.

Clamp probe for non-contact electrical parameter measurement

Systems and methods are provided for measuring electrical parameters in an insulated conductor without requiring a galvanic connection. A non-contact, electrical parameter sensor probe may be operative to measure both current and voltage in an insulated conductor. The sensor probe includes a body, a Rogowski coil coupled to the body, and a non-contact voltage sensor coupled to the body or the Rogowski coil. The size of the loop of the Rogowski coil is selectively adjustable, such that the loop may be tightened around the conductor under test until the conductor is positioned adjacent a portion of the body or Rogowski coil that includes the non-contact voltage sensor. Measured electrical parameters may be provided to a user, e.g., via a display, or may be transmitted to one or more external systems via a suitable wired or wireless connection.

Adjustable length Rogowski coil measurement device with non-contact voltage measurement

Systems and methods for measuring alternating current (AC) voltage of an insulated conductor are provided, without requiring a galvanic connection between the conductor and a test electrode. A non-galvanic contact voltage measurement device includes a conductive sensor, an internal ground guard, and a reference shield. A reference voltage source is electrically coupleable between the guard and the reference shield to generate an AC reference voltage which causes a reference current to pass through the conductive sensor. Sensor subsystems may be arranged in layers (e.g., stacked layers, nested layers, or components) of conductors and insulators. The sensor subsystems may be packaged as formed sheets, flexible circuits, integrated circuit (IC) chips, nested components, printed circuit boards (PCBs), etc. The sensor subsystems may be electrically coupled to suitable processing or control circuitry of a non-contact voltage measurement device to allow for measurement of voltages in insulated conductors.

Sensor subsystems for non-contact voltage measurement devices

Systems and methods provide measurement of alternating current (AC) electrical parameters in an insulated wire without requiring a galvanic connection between the insulated wire and a test probe. Measurement systems or instruments may include a housing that includes both a non-contact voltage sensor and a non-contact current sensor. The measurement system obtains measurements from the voltage sensor and the current sensor during a measurement time interval and processes the measurements to determine AC electrical parameters of the insulated wire. The AC electrical parameters may be presented to an operator via a visual indicator device (e.g., display, lights). The AC electrical parameters may additionally or alternatively be communicated to an external device via a wired and/or wireless communications interface. The measurement system may include an alignment feedback sensor that provides feedback to a user regarding the mechanical alignment of the insulated wire relative to the voltage sensor and the current sensor.

Non-contact electrical parameter measurement systems

Systems and methods for measuring alternating current (AC) voltage of an insulated conductor (e.g., insulated wire) are provided, without requiring a galvanic connection between the conductor and a test electrode or probe. A non-galvanic contact (or 'non-contact') voltage measurement system includes a conductive sensor, an internal ground guard and a reference shield. A common mode reference voltage source is electrically coupled between the internal ground guard and the reference shield to generate an AC reference voltage which causes a reference current to pass through the conductive sensor. At least one processor receives a signal indicative of current flowing through the conductive sensor due to the AC reference voltage and the AC voltage in the insulated conductor, and determines the AC voltage in the insulated conductor based at least in part on the received signal.

Non-contact voltage measurement system using reference signal

Systems and methods of providing a magnetically coupled ground reference probe for use with test equipment, such as digital multimeters (DMMs). The magnetically coupled ground reference probes disclosed herein may be used instead of a typical test probe or alligator clip. A magnetically coupled ground reference probe may be provided which includes an insulative housing surrounding a conductive magnet such as a permanent magnet or an electromagnet. The magnet may autonomously retract into a cavity of the insulative housing when not coupled to a ground reference so that the magnet does not contact a high potential source when being handled by the operator. In at least some implementations, at least a portion of the insulation material of the housing may be compressible to allow the magnet to come into physical contact with a ground reference surface while providing a sufficient creepage and clearance path.

Magnetically coupled ground reference probe

A multimeter includes a case having a rotary selector knob for selecting a multimeter function. A circuit board defining multiple switching terminals thereon is located in the case. A rotary switch assembly is operatively coupled to the selector knob. The rotary switch assembly has a plurality of contact pairs which selectively complete a galvanic connection across predetermined pairs of switching terminals. The rotary switch assembly further includes first and second switch members located in opposition on respective sides of the circuit board. Each of the switch members has at least one of the contact pair.

Digital multimeter having improved rotary switch assembly

A multimeter includes a case defining an interior cavity in which components of the multimeter are located. The case has a top portion defining a plurality of first button apertures. A rotary selector knob is also provided for selecting a multimeter function. The multimeter further includes a separate front panel juxtaposed to the top portion of the case. The front panel has a plurality of second button apertures in respective register with at least some of the first button apertures. The top portion of the case may define a recess in which the front panel is received. The multimeter may also include a flexible keypad located between the top portion of the case and the front panel.

Digital multimeter having a case and a separate panel structure

A multimeter includes a case having a rotary selector knob for selecting a multimeter function. A circuit board defining multiple switching terminals thereon is located in the case. A rotary switch assembly is operatively coupled to the selector knob. The rotary switch assembly has a plurality of contact pairs which selectively complete a galvanic connection across predetermined pairs of switching terminals. The rotary switch assembly further includes first and second switch members located in opposition on respective sides of the circuit board. Each of the switch members has at least one of the contact pairs.

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Seattle, WA, United States of America

Jeffrey E Worones