Fluke Corporation

Monte R Washburn

Mark E Lockman

Carl J Ledbetter

Edmond C Eng

Dennis Lamb

Howard T Voorheis

Steven W Fisher

Christopher W Lagerberg

Michael F Gallavan

John M Lund

Warren H Wong

Jonathan J Parle

William J Lauby

A four-wire ohmmeter connector includes a pair of elongated members spaced apart from each other by an interconnecting web. A pair of elongated contacts are mounted on forwardly projecting portions of each of the elongated members. An insulative housing surrounds the elongated members, contacts and web. The contacts mounted on one of the elongated members are connected through separate wires to a positive probe, and the contacts mounted on the other of the elongated members are connected through separate wires to a negative probe. The elongated members are inserted into respective terminal apertures of a four-wire ohmmeter. A pair of semi-cylindrical conductive sleeves are aligned with each of the apertures, and they make contact with and compress the respective contacts that are inserted into the aperture.

Four-wire ohmmeter connector and ohmmeter using same

A calibrated isothermal assembly for a thermocouple thermometer is provided to obviate a calibration step after manufacture of the instrument. A compact isothermal block is fabricated on a specialized printed circuit board which includes a thick metal plate to establish sufficient thermal mass and good heat conductivity. A temperature sensor is mounted at the thermocouple reference junction on the printed circuit board to track the reference junction temperature. The calibrated isothermal assembly also includes a current source for the temperature sensor, and a memory device containing stored calibration data specific to the temperature sensor.

Calibrated isothermal assembly for a thermocouple thermometer

Digital electronic instrument

A voltage measurement instrument such as a digital multimeter is provided with transient overvoltage input protection. Internal walls are integrally molded with the instrument case and disposed in close proximity to the input receptacles and terminals to separate conductive surfaces and provide transient overvoltage barriers. Top and bottom wall portions are fitted together in tongue-and-groove fashion to increase the creepage and clearance path without increasing the linear distance between conductive surfaces. This arrangement also allows the instrument to maintain a low profile.

Voltage measurement instrument having transient overvoltage input

A cover assembly for restraining an object in an enclosure has a cover frame defining an opening at an open end of the enclosure, a cover to cover the opening, a restraining mechanism securing the cover to the cover frame to restrict movement of the cover relative to the cover frame when the cover is in a closed position and thereby restrain the object in the enclosure, and a latch to secure the cover to the cover frame to also restrict movement of the cover relative to the cover frame when the cover is in a closed position. A method for restraining the object in the enclosure includes securing the cover to the cover frame to cover the opening, securing the cover to the cover frame to restrict movement of the cover relative to the cover frame, and unsecuring the cover from the cover frame with a force having a first component force which unsecures the cover from the cover frame and a second component force which moves the cover relative to the cover frame.

Cover assembly for restraining an object in an enclosure

A compact isothermal connector for a thermocouple temperature measurement system has electrical contacts with thermal mass sufficiently larger than the thermal mass of the corresponding contacts of a corresponding thermocouple connector to provide for improved settling times and measurement accuracy. The contacts are thermally coupled to a multi-layer printed circuit board containing layers of embedded thermally conducting material to achieve sufficient thermal coupling between the contacts. The contacts have sufficient thermal mass to achieve a desired settling time. A temperature sensor is thermally coupled to the printed circuit board and to each electrical contact to sense the temperature of the isothermal connector and provide the temperature information to a temperature measuring instrument to correct for measurement errors from the connector junction voltage.

Compact thermocouple connector

Documenting process calibrator

Pressure module

Growing community of inventors

Bothell, WA, United States of America

Monte R Washburn