Abstract:
A micromachined device (32) receiving a pressurizable fluid has a plurality of layers (34, 36) bonded together along at least one bond interface (35), the bond interface having a terminus bordering the pressurizable fluid. In a vicinity of at least one bond interface (35) at least one layer (34, 36) has a shape that reduces a stress magnitude near the bond terminus. In a preferred embodiment a width of at least one layer (34) increases toward the bond interface (35), to increase the pressure at which the device can operate without fracturing. In another embodiment, both layers (34, 36) bordering the bond interface (35) have widths in the vicinity of the bond interface (35) that increase toward the bond interface (35). Alternately, the layers (34, 36) have walls shaped such that, for a reference line perpendicular to the bond interface (35) and passing through an end of the bond interface (35) bordering the cavity, the cavity protrudes between the reference line and at least one of the walls.
Abstract:
An electrically variable optical attenuator (100, 200, 300, 400, 500, 602, 604, 606) and associated methods are disclosed. In one aspect, the attenuator (100, 200, 300, 400, 500, 602, 604, 606) includes at least one sensor 710 that provides a sensor output with respect to a variable that affects attenuation. Methods of characterizing the attenuator (100, 200, 300, 400, 500, 602, 604, 606) include obtaining a set of attenuation/sensed variable data, and generating a relationship (such as a look-up table or mathematical function) relating the sensed variable to the attenuation. Aspects of the invention also include characterizing the control input/attenuation output to be related by a selected mathematical function.
Abstract:
A process control system (10) utilizes wireless transceivers to divorce the field devices (14, 30) from traditional wired network topologies. By providing field devices (14, 30) with wireless transceivers (22) and shared wireless transceivers (36) for adapting wired field devices (30), the field device network may be adapted to any number of network topologies without concern for additional wiring costs. Specifically, a power supply (18, 26) can be provided for each field device (14) or for groups of field devices, as needed. Thus, the entire network can receive power from a single power bus (32), without expensive power filtering. In addition, the network can be a hybrid in which part of the information is transmitted and received over wired lines and part is transmitted and received over wireless communications.
Abstract:
A pressure sensor assembly (100) includes an elongate pressure sensor (102) mounted to a sensor mounting block (104). A protective element covers (120) the elongate pressure sensor (102) to prevent the pressure sensor from contacting process fluid.
Abstract:
A process device (10) has a process seal (48, 52) for coupling to an industrial process. The process device (10) includes a process device body (14, 250) having an isolation cavity and an isolation passageway (32, 34) extending from the isolation cavity to a pressure sensor (16). The isolation cavity and isolation passageway (32, 34) filled with an isolation fluid. An isolation diaphragm (254) is positioned to isolate the isolation cavity from process fluid. The isolation diaphragm (254) has a process fluid side and an isolation fluid side. A weld ring (200) is positioned around a periphery of the process fluid side of the isolation diaphragm (254). The weld ring (200) is formed of a first material compatible with the isolation diaphragm and a second material compatible with the process device body (14, 250). A weld (258) secures the weld ring (200) to the process device body (14, 250).
Abstract:
A pressure transmitter (12) with pressure sensor mount includes pressure measurement circuitry (62). A metal body (100) of the pressure transmitter has a pressure coupling configured to couple to a process pressure P. A pressure sensor (40) is configured to provide an output related to an applied pressure to the pressure measurement circuitry. A conduit (120) is coupled to the pressure sensor (40) and configured to apply an applied pressure corresponding to the process pressure to pressure sensor. A non-conductive spacer (110) is configured to electrically isolate the conduit (120) from the metal body (100). The non-conductive spacer (110) has an opening (112) formed therein and is arranged to convey the applied from the metal body (100) to the conduit (120).
Abstract:
A differential pressure transmitter (200; 300; 400; 500; 600; 700) includes first (210; 310) and second (212;312) process fluid inlets. A differential pressure sensor (214; 338; 518; 638) is disposed within the transmitter (200; 300; 400; 500; 600; 700) and has first and second sensor inlets. A first isolator diaphragm (230; 330) is located proximate the first process fluid inlet (210; 310) and is operably coupled to the first sensor inlet through a first fill fluid volume (334). A second isolator diaphragm (232; 332) is located proximate the second process fluid inlet (212;312) and is operably coupled to the second sensor inlet through a second fill fluid volume (336). Measurement circuitry (218) is operably coupled to the differential pressure sensor (214; 338; 518; 638) and configured to measure an electrical parameter of the sensor (214; 338; 518; 638) and provide an indication of the measured parameter. A third fluid volume (354) substantially surrounds the differential pressure sensor. The third fluid volume (354) exerts a compressive force on the differential pressure sensor (214; 338; 518; 638).
Abstract:
A pressure transmitter (100) comprises a metal wall (102) separating a process pressure chamber (104) from an electronics compartment (106). The metal wall (102) has a stepped bore (108) with a bore shelf (110) facing the process pressure chamber (104). A metal header (112) has a stepped outer rim (114) with a header shelf that contacts the bore shelf. The metal header (112) includes at least one electrical feedthrough (122,124) with a glass-to-metal seal (126,128) adjacent the stepped outer rim (114). A welded seal (130) seals the stepped outer rim to the stepped bore.
Abstract:
A pressure sensing capsule (20) includes a pressure sensor (28) inside a capsule wall (34). The capsule wall includes a feedthrough opening (40). The pressure sensor is mounted to a stress isolation member (48) with a feedthrough hole (50). The pressure sensor is mounted to the stress isolation member with the feedthrough hole overlying electrical contacts (46) on the pressure sensor.
Abstract:
A deflecting diaphragm differential pressure sensor (10) is formed so all electrical elements (30A-30D) and connections (34B) from external circuitry to the sensor (10) are isolated from the pressure media. The deflecting, pressure sensing diaphragm (22) is made of a semi-conductor material, having piezoresistors disposed on a surface (25) thereof to form strain gages to sense deflection of the diaphragm (22). The strain gage resistors are media isolated by a layer that overlies the strain gage resistors. All forms of the invention provide environmental protection for the electrical connections for external circuitry, which are subject to corrosion from the pressure media.