ROBERT H JOHNSON
Electrician in Pembroke, MA

License number
Massachusetts 26486
Issued Date
Mar 22, 1982
Expiration Date
Jul 31, 2019
Type
Journeyman Electrician
Address
Address
Pembroke, MA 02359

Personal information

See more information about ROBERT H JOHNSON at radaris.com
Name
Address
Phone
Robert M. Johnson
Shrewsbury, MA
(508) 842-7403
Robert L. Johnson
Gardner, MA
(978) 632-6905
(978) 632-4167
Robert L. Johnson
Haverhill, MA
(978) 374-5386

Professional information

Robert Johnson Photo 1

Housing For A Portable Gas Analyzer

US Patent:
D443243, Jan 19, 1999
Filed:
Oct 25, 1996
Appl. No.:
D/061581
Inventors:
Richard H. Seager - Mystic CT
Norman P. Bridges - Cedar Park TX
Robert E. Johnson - Pembroke MA
Assignee:
The Foxboro Company - Foxboro MA
International Classification:
1004
US Classification:
D10 81


Robert Johnson Photo 2

Optical Spectral Filter And Linear Positioner Therefor

US Patent:
5793545, Aug 11, 1998
Filed:
Oct 25, 1996
Appl. No.:
8/740287
Inventors:
Stephen L. Monfre - Plainville MA
Anthony C. Jeannotte - Foxboro MA
Richard H. Seager - Mystic CT
Norman P. Bridges - Cedar Park TX
Robert E. Johnson - Pembroke MA
Assignee:
The Foxboro Company - Foxboro MA
International Classification:
G02B 522
US Classification:
359891
Abstract:
A multi-wavelength optical filter for a portabe gas analyzer includes a filter assembly having a first opening and multiple additional openings. The first opening has a linearly variable filter disposed therein, while the additional openings have discrete filters disposed therein. The filters are linearly aligned, such that filter selection is facilitated by using the filter assembly with a linear positioning mechanism.


Robert Johnson Photo 3

Smoke Detector Of The Ionization Type

US Patent:
4455553, Jun 19, 1984
Filed:
May 17, 1982
Appl. No.:
6/378400
Inventors:
Robert E. Johnson - Pembroke MA
Assignee:
Pyrotector, Inc. - Hingham MA
International Classification:
G08B 1710
US Classification:
340629
Abstract:
An ionization type smoke detector (10) includes a chamber having a measuring electrode (12), the voltage on the measuring electrode being a function of the concentration of smoke in the chamber, and further includes a comparison device (A3) for comparing the voltage measured on electrode (12) at two different times, and an output device (K) for producing an output signal if the voltages differ by a predetermined value.


Robert Johnson Photo 4

Ionization Type Smoke Detector With Test Circuit

US Patent:
4456907, Jun 26, 1984
Filed:
Apr 26, 1983
Appl. No.:
6/487356
Inventors:
Robert E. Johnson - Pembroke MA
Assignee:
Pyrotector, Inc. - Hingham MA
International Classification:
G08B 1710
US Classification:
340629
Abstract:
An ionization detector of the type having a housing with electrodes and a radiation source for causing ion current flow between the electrodes, collector means for detecting, by a change in voltage, a drop in ion current flow, and means responsive to a predetermined change in collector voltage to provide an output signal, in which a test electrode is provided in the housing and means is provided for applying to the test electrode a predetermined voltage of a value that causes said predetermined change in voltage at the collector, whereby said output signal is provided when said predetermined voltage is applied to the test electrode if said detector is operating satisfactorily.


Robert Johnson Photo 5

Smoke Detector

US Patent:
4564762, Jan 14, 1986
Filed:
May 16, 1984
Appl. No.:
6/610760
Inventors:
Charles F. Doherty - Quincy MA
Robert E. Johnson - Pembroke MA
Assignee:
Pyrotector, Inc. - Hingham MA
International Classification:
G01T 1185
US Classification:
250381
Abstract:
An ionization detector unit for use in a smoke detector includes a housing wall enclosing an ionization chamber, the wall having openings for passage of air through the chamber, the frontal surface of the wall that is exposed to an oncoming air flow from a given direction being inclined relative to an intersecting second surface exposed to the flow. The frontal surface is shaped and positioned to deflect the air flow generally toward the second surface, and the second surface is shaped and positioned to deflect the air flow generally toward the frontal surface, the shape and position of the surfaces cooperatively arranged to cause the deflected air flows to converge and form a region of air in the vicinity of the intersection of the surfaces that is at higher pressure and slower velocity than the oncoming air flow. Apertures are provided in the frontal surface of the housing to enable entry of air from the vicinity of the intersection to establish relatively slow, laminar air flow through the chamber, thereby to enable an effective ion current to be maintained within the chamber despite high velocity of oncoming air.