Measuring and testing – Fluid pressure gauge – Electrical
Reexamination Certificate
2001-05-30
2003-04-15
Williams, Hezron (Department: 2855)
Measuring and testing
Fluid pressure gauge
Electrical
C073S706000, C073S861420
Reexamination Certificate
active
06546805
ABSTRACT:
FIELD OF THE INVENTION
This invention relates to transmitters used in industrial fluid processing plants. In particular, this invention relates to an improved arrangement for field programming switches in process fluid transmitters.
BACKGROUND OF THE INVENTION
Modern industrial process fluid transmitters often have embedded microprocessors and are field programmable to adjust span, zero, alarm, security or other settings.
In some installations, these setting are programmed by temporarily connecting a handheld serial communication device to the transmitter's two-wire field circuit. It can be complex and time consuming, however, to find and connect the device and enter programming commands via a keyboard on the device.
In other installations, there are programming switches that are easier to program inside the transmitter circuit board housing. This arrangement, however, has certain disadvantages. In order to use these programming switches in the field, the circuit board housing is opened up in the process plant atmosphere. This exposes sensitive transmitter circuitry to atmospheric humidity, moisture or chemicals.
In some transmitters, the problem is addressed by using magnetically actuated reed switches so that the transmitter circuit board housing does not need to be opened. The arrangement with reed switches, however, is expensive to implement and only a small number of switches can be used because of size limitations.
Programming switch circuitry is energized, along with the rest of the transmitter circuitry, by the two-wire field circuit that provides a 4-20 mA current with a voltage range of 10.5-55 volts. The transmitter must be designed to be fully operational on 4 mA and 10.5 volts, or only about 42 milliwatts. This means that any bias or “pull-up” resistors for the switch circuitry must be high impedance to limit power consumption. With such high impedance circuits, even small amounts of chemicals, water, or humidity can cause electrical leakage in the switch circuitry. This leakage can cause a false indication to transmitter circuitry that a switch has been actuated.
There is a desire to have a transmitter that has sensor circuit boards in a permanently sealed housing and also multiple programming switches placed outside the permanently sealed circuit board housing. There is also a desire to avoid false indication from programming switch circuits due to contamination, water or humidity in the environment.
SUMMARY OF THE INVENTION
An environmentally sealed service block is mounted on mounting ears inside a field wiring compartment of a process fluid transmitter. The service block includes sealed programming jumper assemblies and sealed programming pushbutton switches. The service block also includes a sealed cable that connects to the pushbutton switches, the jumper assemblies and field wiring terminals. The sealed cable has a plug that plugs into a transmitter electrical connector of a permanently sealed transmitter assembly.
Circuitry connected to the jumper assemblies and pushbutton switches is effectively sealed and not subject to malfunction due to contamination present in the field wiring compartment. The transmitter assembly remains permanently sealed when the programming jumper assemblies or pushbutton switches are actuated.
REFERENCES:
patent: 3701280 (1972-10-01), Stroman
patent: 3968694 (1976-07-01), Clark
patent: 4120206 (1978-10-01), Rud, Jr.
patent: 4125027 (1978-11-01), Clark
patent: 4238825 (1980-12-01), Geery
patent: 4250490 (1981-02-01), Dahlke
patent: 4287501 (1981-09-01), Tominaga et al.
patent: 4414634 (1983-11-01), Louis et al.
patent: 4419898 (1983-12-01), Zanker et al.
patent: 4446730 (1984-05-01), Smith
patent: 4455875 (1984-06-01), Guimard et al.
patent: 4485673 (1984-12-01), Stern
patent: 4528855 (1985-07-01), Singh
patent: 4562744 (1986-01-01), Hall et al.
patent: 4598381 (1986-07-01), Cucci
patent: 4602344 (1986-07-01), Ferretti et al.
patent: 4617607 (1986-10-01), Park et al.
patent: D287827 (1987-01-01), Broden
patent: 4644797 (1987-02-01), Ichikawa et al.
patent: 4653330 (1987-03-01), Hedtke
patent: 4677841 (1987-07-01), Kennedy
patent: 4745810 (1988-05-01), Pierce et al.
patent: D296995 (1988-08-01), Lee
patent: D297314 (1988-08-01), Hedtke
patent: D297315 (1988-08-01), Pierce et al.
patent: 4783659 (1988-11-01), Frick
patent: 4791352 (1988-12-01), Frick et al.
patent: 4798089 (1989-01-01), Frick et al.
patent: 4818994 (1989-04-01), Orth et al.
patent: 4825704 (1989-05-01), Aoshima et al.
patent: 4833922 (1989-05-01), Frick et al.
patent: 4850227 (1989-07-01), Luettgen et al.
patent: 4866989 (1989-09-01), Lawless
patent: 4881412 (1989-11-01), Northedge
patent: 4930353 (1990-06-01), Kato et al.
patent: 4958938 (1990-09-01), Schwartz et al.
patent: 4970898 (1990-11-01), Walish et al.
patent: 4980675 (1990-12-01), Meisenheimer, Jr.
patent: 5000047 (1991-03-01), Kato et al.
patent: D317266 (1991-06-01), Broden et al.
patent: D317269 (1991-06-01), Selg
patent: D318432 (1991-07-01), Broden et al.
patent: 5028746 (1991-07-01), Petrich
patent: 5035140 (1991-07-01), Daniels et al.
patent: 5051937 (1991-09-01), Kawate et al.
patent: 5058437 (1991-10-01), Chaumont et al.
patent: 5060108 (1991-10-01), Baker et al.
patent: 5070732 (1991-12-01), Duncan et al.
patent: 5083091 (1992-01-01), Frick et al.
patent: 5087871 (1992-02-01), Losel
patent: 5094109 (1992-03-01), Dean et al.
patent: D329619 (1992-09-01), Cartwright
patent: 5142914 (1992-09-01), Kusakabe et al.
patent: 5157972 (1992-10-01), Broden et al.
patent: 5162725 (1992-11-01), Hodson et al.
patent: 5187474 (1993-02-01), Kielb et al.
patent: 5212645 (1993-05-01), Wildes et al.
patent: 5227782 (1993-07-01), Nelson
patent: 5236202 (1993-08-01), Krouth et al.
patent: 5245333 (1993-09-01), Anderson et al.
patent: 5248167 (1993-09-01), Petrich et al.
patent: D342456 (1993-12-01), Miller et al.
patent: 5276631 (1994-01-01), Popovic et al.
patent: 5287746 (1994-02-01), Broden
patent: 5353200 (1994-10-01), Bodin et al.
patent: 5369386 (1994-11-01), Alden et al.
patent: 5377547 (1995-01-01), Kusakabe et al.
patent: 5381355 (1995-01-01), Birangi et al.
patent: D358784 (1995-05-01), Templin, Jr. et al.
patent: 5436824 (1995-07-01), Royner et al.
patent: 5448180 (1995-09-01), Kienzler et al.
patent: 5469150 (1995-11-01), Sitte
patent: 5471885 (1995-12-01), Wagner
patent: D366000 (1996-01-01), Karas et al.
patent: D366218 (1996-01-01), Price et al.
patent: 5495768 (1996-03-01), Louwagie et al.
patent: 5498079 (1996-03-01), Price
patent: 5502659 (1996-03-01), Braster et al.
patent: 5524333 (1996-06-01), Hogue et al.
patent: 5524492 (1996-06-01), Frick et al.
patent: 5546804 (1996-08-01), Johnson et al.
patent: 5600782 (1997-02-01), Thomson
patent: 5606513 (1997-02-01), Louwagie et al.
patent: 5650936 (1997-07-01), Loucks et al.
patent: 5656782 (1997-08-01), Powell, II et al.
patent: 5665899 (1997-09-01), Willcox
patent: 5668322 (1997-09-01), Broden
patent: 5669713 (1997-09-01), Schwartz et al.
patent: 5670722 (1997-09-01), Moser et al.
patent: 5677476 (1997-10-01), McCarthy et al.
patent: 5710552 (1998-01-01), McCoy et al.
patent: 5754596 (1998-05-01), Bischoff et al.
patent: 5764928 (1998-06-01), Lancott
patent: 5823228 (1998-10-01), Chou
patent: 5870695 (1999-02-01), Brown et al.
patent: 5899962 (1999-05-01), Louwagie et al.
patent: 5920016 (1999-07-01), Broden
patent: 5948988 (1999-09-01), Bodin
patent: 5954526 (1999-09-01), Smith
patent: 5955684 (1999-09-01), Gravel et al.
patent: 5973942 (1999-10-01), Nelson et al.
patent: 5988203 (1999-11-01), Hutton
patent: 6005500 (1999-12-01), Goboury et al.
patent: 6006338 (1999-12-01), Longsdorf et al.
patent: 6038927 (2000-03-01), Karas
patent: 6050145 (2000-04-01), Olson et al.
patent: 6059254 (2000-05-01), Sundet et al.
patent: 6105437 (2000-08-01), Klug et al.
patent: 6111888 (2000-08-01), Green et al.
patent: 6115831 (2000-09-01), Hanf et al.
patent: 6123585 (2000-09-01), Hussong et al.
patent: 6131467 (2000-10-01), Miyano et al.
patent: 6140952 (2000-10-01), Gaboury
patent: 6151557 (2000-11-01), Broden et al.
patent: 6216172 (2001-04-01), Kolblin
Fandrey Mark C.
Hausler George C.
LaRoche Robert
Ellington Alandra
Rosemount Inc.
Westman Champlin & Kelly P.A.
Williams Hezron
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