Customized Process Variable Transmitters with Sealed Electronics

Abstract

The process variable transmitter (102) includes a process variable sensor (110) and an electromagnetic interference (EMI) protection circuit (182) coupled to the process variable sensor (110). The process variable transmitter (102) also includes an enclosed module (104) that encloses the EMI protection circuit (182) and electrical connectors (132, 134, 136) coupled to the EMI protection circuit (182) within the enclosed module (104). The electrical connectors (132, 134, 136) are configurable from outside the enclosed module (104) such that the electronic components of the EMI protection circuit (182) are connected in a configuration that provides transient protection.

Description

[Background technology]

[0001] In the process control industry, process transmitters are often installed in or near corrosive / hazardous environments. Therefore, in some process transmitter designs, the transmitter electronics are housed in a hermetically sealed package with flying leads as the customer interface to simplify approval requirements. To achieve the hermetic package, a limited number of electrical signals pass through a sealed header interface.

[0002] Industrial process transmitters are typically offered with standard or transient protection options, which provide additional protection against lightning and other unintentional surges, but also require additional transient suppression electronics that must be protected from environmental conditions. Summary of the Invention [Problem to be solved by the invention]

[0003] Embodiments of the present disclosure provide a process variable transmitter design in which one common sealed module can provide both standard and transient protection options by routing the signal from the sealed header to the output connector during final assembly, thereby overcoming some hazardous location approval hurdles and providing late-stage customization capabilities, thereby reducing module inventory. [Means for solving the problem]

[0004] In one embodiment, a process variable transmitter is provided. The process variable transmitter includes a process variable sensor and an electromagnetic interference (EMI) protection circuit coupled to the process variable sensor. The process variable transmitter also includes an enclosed module that encloses the EMI protection circuit and an electrical connector coupled to the EMI protection circuit within the enclosed module. The electrical connector is configurable from outside the enclosed module to connect electronic components of the EMI protection circuit in a configuration that provides transient protection.

[0005] In another embodiment, a method is provided that includes enclosing an electromagnetic interference (EMI) protection circuit coupled to a process variable sensor in an enclosed module having an electrical connector extending to an exterior thereof, and connecting electronic components of the EMI protection circuit from the exterior of the enclosed module through the electrical connector in a configuration that provides transient protection.

[0006] In yet another embodiment, a process variable transmitter is provided. The process variable transmitter includes a process variable sensor and an electromagnetic interference (EMI) protection circuit coupled to the process variable sensor. The process variable transmitter also includes an enclosed module that encloses the EMI protection circuit. The enclosed module has a first end including a feedthrough body and a plurality of feedthrough pins that extend through the feedthrough body and are sealed to the feedthrough body. The feedthrough pins are coupled to the EMI protection circuit within the enclosed module and are configurable from outside the enclosed module so that electronic components of the EMI protection circuit are connected in a configuration that provides transient protection.

[0007] This Summary is provided to introduce a selection of concepts in a simplified form that are further described below in the Detailed Description. This Summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended for use as an aid in determining the scope of the claimed subject matter. The claimed subject matter is not limited to implementations that solve any or all of the disadvantages noted in the Background. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a partial cross-sectional view of an example of a process control system including a pressure transmitter in which embodiments of the present disclosure may be utilized. [Figure 2] FIG. 2 is a simplified block diagram of the pressure transmitter of FIG. 1. [Figure 3]FIG. 1 is a schematic diagram illustrating an electrical configuration in which components for transient or electromagnetic interference (EMI) protection are external to the enclosed module of the process transmitter. [Figure 4] 1 shows an enclosed module containing EMI protection circuitry and an output assembly that does not include EMI protection components. [Figure 5] FIG. 1 is a schematic diagram illustrating an enclosed module-output assembly configuration with an additional feedthrough routed to electrical ground to enable transient protection according to one embodiment. [Figure 6] FIG. 10 is a schematic diagram showing an enclosed module-output assembly configuration with additional feedthroughs routed back to their respective lines for units without transient protection. DETAILED DESCRIPTION OF THE INVENTION

[0009]

[0023] Hereinafter, embodiments of the present invention will be described in more detail with reference to the accompanying drawings. Elements identified with the same or similar reference characters are intended to refer to the same or similar elements. For clarity of the drawings, some elements may not be shown in every figure. Various embodiments of the present disclosure may be embodied in many different forms and should not be construed as being limited to the specific embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art.

[0010] FIELD OF THE DISCLOSURE Embodiments of the present disclosure generally relate to customizing process variable transmitters with sealed electronics. More specifically, embodiments of the present disclosure provide a common sealed module that can be reconfigured after assembly to provide standard or transient protection options while meeting hazardous location approval requirements. Before providing details regarding different embodiments, an exemplary process control system including a process transmitter is described below.

[0011] Figure 1 illustrates an example process control system that may incorporate certain embodiments disclosed herein. The process control system illustrated in Figure 1 is for illustrative purposes only. Embodiments of the present disclosure are not limited to a particular process control system such as the process control system illustrated in Figure 1. Embodiments of the present disclosure are illustratively implemented in many different types of process control systems.

[0012] Figure 1 is a schematic, partial cross-sectional view of an example process control system 100 including a process variable transmitter (e.g., a pressure transmitter) 102 that can utilize embodiments of the present disclosure. Figure 2 is a simplified block diagram of the transmitter 102 of Figure 1. The system 100 can be used in the processing of materials (e.g., process media) to convert the materials from a less valuable state into more valuable and useful products, such as petroleum, chemicals, paper, food, etc. For example, the system 100 can be used in facilities that perform sanitary or other types of industrial processes.

[0013] The pressure transmitter 102 may include a housing 104 that can be coupled to an industrial process 106 via a process coupling 108. The housing 104 and the process coupling 108 may be formed of stainless steel or other suitable materials. The transmitter 102 includes a pressure sensor assembly 110, including a pressure sensor 112, and measurement circuitry 114 within the housing 104. The measurement circuitry 114 may include processing / computing circuitry, communication circuitry, and electromagnetic interference (EMI) protection circuitry. In the transmitter 102, a first end 116 of the housing 104 surrounds and contacts an outer surface of a feedthrough body 118 for electrical connection, as described further below, and is hermetically sealed to the feedthrough body 118 by brazing, welding, or other suitable technique. Similarly, a second end 120 of the housing 104 is hermetically sealed using any suitable technique to create a sealed chamber in which the pressure sensor assembly 110 and measurement circuitry 114 are housed.

[0014] The process coupling 108 is connected to the process 106 and may be connected to a pipe 121 containing a process material (e.g., a fluid) at a pressure P that is measured by a pressure sensor 112. The pressure P is transmitted to the pressure sensor 112 through a fluid path 122. The pressure sensor 112 includes a sensor element having an electrical parameter indicative of the applied pressure P. A measurement circuit 114 may detect and process the sensor element's electrical parameter through suitable electrical connections 124 to determine the value of the sensed pressure P. The measured pressure value and other information form the measurement circuit 114 are transmitted to an external computerized control unit 126 in a remotely located control room 127 via suitable output electrical connections 128 and a process control loop 130, as shown in FIG. 1 .

[0015] As best seen in FIG. 2 , the output electrical connection 128 has three electrical connectors (e.g., wires), including a first active connector 132, a second active connector 134, and an electrical ground connector 136. More or fewer connectors may be used. First ends of the connectors 132, 134, and 136 are coupled to feedthrough pins 138, 140, and 142, respectively, which pass through the feedthrough body 118 and are sealed to the feedthrough body 118 by a sealant, such as glass or ceramic. For example, the pin 142 passes through an opening 144 in the feedthrough body 118 and is sealed to the feedthrough body 118 by a cylindrical glass seal layer 156. Second ends of the wires 132, 134, and 136 may be connected, for example, to bond pads on a printed circuit board of the transmitter measurement circuit 114. The feedthrough body 118 and the feedthrough pins 138, 140, and 142 may be referred to herein as headers.

[0016] As shown in FIGS. 1-2 , the transmitter 102 includes an output assembly 158 that is removably coupleable to the housing 104. The output assembly 158 includes a housing 160, an output interface 162, and flying leads 164, 166, and 168 coupled to the output interface 162. The portions of the output interface 162 and the flying leads 164, 166, and 168 within the housing 160 are encapsulated with any suitable material 170. When the output assembly 158 is coupled to the housing 104 as shown in FIG. 1 , the flying leads 164, 166, and 168 are electrically connected to the output interface 162 and the connectors 132, 134, and 136 via the respective feedthrough pins 138, 140, and 142. The flying lead 168 is connected to electrical ground, and the flying leads 164 and 166 are connected to the process control loop 130.

[0017] Communication between the control unit 126, or another external computing device, and the pressure transmitter 102 can occur over the control loop 130 according to conventional analog and / or digital communication protocols. In some embodiments, the two-wire control loop 130 comprises a 4-20 milliamp control loop, and the measured pressure value can be represented by the level of loop current flowing through the two-wire control loop 130. An exemplary digital communication protocol includes modulation of a digital signal onto an analog current level on the two-wire control loop 130, such as according to the HART® communication standard. Other purely digital techniques, including FieldBus and Profibus communication protocols, can also be used.

[0018] In some embodiments, wireless communication between the transmitter 102 and the control unit 130 may also be provided. Exemplary wireless versions of the process control loop 130 include, for example, a wireless mesh network protocol such as WirelessHART® (IEC 62591) or ISA 100.11a (IEC 62734), or another wireless communication protocol such as WiFi, LoRa, Sigfox, BLE, or any other suitable protocol.

[0019] Power can be provided to the pressure transmitter 102 from any suitable power source. For example, the pressure transmitter 102 may be powered entirely by the current flowing through the control loop 130. Alternatively, one or more power sources, such as an internal or external battery, can be utilized to power the pressure transmitter 102. Alternatively, a generator (e.g., solar panels, wind turbines, etc.) can be used to power the pressure transmitter or to charge the power source used by the pressure transmitter 102.

[0020] It may be desirable to manufacture a sealed module (e.g., the housing 104 with the internal components shown in FIGS. 1 and 2) for an industrial process variable transmitter (e.g., the pressure transmitter 102 of FIGS. 1 and 2) in one location and then allow for later customization of standard or transient protection options at a different final assembly location. One technique for achieving this is to place the components providing transient protection on a printed circuit assembly (PCA) external to the sealed module. When this approach is utilized for the process transmitter 102 of FIGS. 1 and 2, the output interface 162 would include the PCA, which provides the connection between the sealed module 104 and the flying leads 164, 166, and 168 for the customer interface. The assembly of the PCA and flying leads 164, 166, and 168 is immersed in an encapsulant 170 to meet hazardous location approval requirements.

[0021] FIG. 3 is a schematic diagram illustrating an electrical structure 180 in which transient protection components are external to the enclosed module 104A of a process transmitter. The enclosed module 104A includes a first active electrical connector 132A, a second active electrical connector 134A, and an electrical ground connector 136A. For simplicity, other circuitry and components within the enclosed module 104A (such as the sensor assembly 110 of FIG. 1) are not shown. An output assembly 158A, which is removably coupleable to the enclosed module 104A, includes an EMI protection circuit 182 that electrically connects to connectors 132A, 134A, and 136A via electrical connectors 132B, 134B, and 136B, respectively. The EMI protection circuit 182 includes capacitors C1 and C2, transient voltage suppression (TVS) diodes D1 and D2, a gas discharge tube GT1, and resistors R1 and R2. As shown in FIG. 3 , a first capacitor C1 is connected between the active electrical connector 132B and the electrical ground connector 136B, and a second capacitor C2 is connected between the active electrical connector 134B and the electrical ground connector 136B. Each capacitor C1 and C2 has a capacitance value of 1500 picofarads (pF) or other suitable capacitance value. Capacitors C1 and C2 delay voltage or current changes in circuit 182 due to inductive transients. TVS diodes D1 and D2 are bidirectional TVS diodes, represented in one embodiment by two opposing avalanche diodes connected in series. The first TVS diode D1 is connected between the active electrical connector 132B and the electrical ground connector 136B, and the second TVS diode D2 is connected between the active electrical connector 134B and the electrical ground connector 136B. Each TVS diode D1 and D2 may have a standoff or breakdown voltage of 70 volts (V) or other suitable breakdown voltage value. TVS diodes D1 and D2 operate by blocking excess current when the induced voltage exceeds their breakdown voltage. Once the overvoltage is removed, TVS diodes D1 and D2 automatically reset.Gas discharge tube GT1 is a three-electrode gas discharge tube with a first electrode 1 connected to active electrical connector 132B, a second electrode 2 connected to electrical ground connector 136B, and a third electrode 3 connected to active electrical connector 134B. The three electrodes 1, 2, and 3 allow a single gas discharge tube GT1 to be used to protect circuit 182. When a voltage exceeding its rated breakdown voltage is applied to gas discharge tube GT1, the gas within gas discharge tube GT1 ionizes and becomes conductive, eventually reaching an impulse discharge voltage. At this point, gas discharge tube GT1 is in a fully on state, maintaining a low arc voltage regardless of the discharge current. After the transient has passed, gas discharge tube GT1 resets to a non-conductive state. Gas discharge tube GT1 may have an impulse discharge voltage value of 90V or other suitable impulse discharge voltage value.

[0022] Resistors R1 and R2 are included in EMI protection circuit 182 to provide protection from the time a transient is initially induced until gas discharge tube GT1 reaches its impulse firing voltage. In the embodiment of FIG. 2, resistor R1 is connected in series with active electrical connector 132B, and resistor R2 is connected in series with active electrical connector 134B. Resistors R1 and R2 may be wirewound, axial, etc., and may have any suitable resistance value. As described above in connection with FIGS. 1 and 2, the PCA, including the EMI protection circuit 182 and flying wires 164, 166, 168 assembly, is immersed in encapsulant 170 to meet hazardous location approval requirements.

[0023] It may also be desirable to utilize additional protection types in the transmitter design, such as Ex mb (sealed to provide a higher level of safety) or Ex eb (explosion protection in accordance with the "Enhanced Safety for Zone 1" standard). However, there are additional safety requirements that make approval difficult. For example, components that are considered to pose an ignition risk, such as capacitors (e.g., C1 and C2 in Figure 3), gas-filled discharge tubes (e.g., GT1 in Figure 3), and resistors (e.g., R1 and R2 in Figure 3), must be immersed in cemented joints that have passed high-pressure hydrostatic tests before and after long-term thermal aging.

[0024] In one instance, water ingress at the output assembly / header interface during high-pressure testing resulted in the test finding that the product did not meet the approval criteria for additional protection types such as Ex mb or Ex eb.

[0025] One technique for meeting the approval requirements for additional protection types involves moving all electrical components for transient protection (e.g., EMI protection circuit 182) into an enclosed module. This simplifies the approval process for the output assembly 158, which includes only the assembly of flying wires 164, 166, and 168 immersed in encapsulant 170, providing a straightforward approach to meeting the approval requirements. However, using two versions of the enclosed module—one for standard protection and one for transient protection—doubles the number of enclosed modules. Figure 4 shows an enclosed module 104B that includes the EMI protection circuit 182 and an output assembly 158B that does not include EMI protection components. For clarity, the assembly of flying wires 164, 166, and 168 is not shown in Figure 4. The enclosed module for the standard option is not shown.

[0026] To address the complexity, cost, and early customization issues associated with having two different versions of a sealed module, an alternative solution is provided, which is described below in connection with Figures 5 and 6.

[0027] The embodiments of the present disclosure described herein in connection with Figures 5 and 6 provide a structure in which the electronics within a hermetically sealed package are reconfigurable after assembly while still meeting hazardous location approval requirements. Late-stage customization of standard and transient outputs is selected at the hub during final assembly. The cost, complexity, and logistics issues associated with the structure described above in connection with Figure 4 are avoided. Also, Safety Zone 1 approval is simplified because no components are located within the enclosed area of ​​the output assembly.

[0028] Similar to the structure of Figure 4, the structures shown in Figures 5 and 6 move the electronics into a sealed module. However, the connections to the protection diodes D1 and D2 and the gas discharge tube GT1 are brought outside the sealed package using additional feedthroughs on the existing header. Late-stage customization is achieved by attaching different wire interface boards during final assembly.

[0029] FIG. 5 is a schematic diagram illustrating a first encapsulated module 104C-output assembly 158C configuration in which additional feedthroughs 184 and 186 are routed to ground to provide transient protection according to one embodiment. As seen in FIG. 5, the encapsulated module 104C includes an EMI protection circuit 182 having transient protection elements connected to the additional feedthroughs 184 and 186. More specifically, feedthrough 184 is connected to a first TVS diode D1, and feedthrough 186 is connected to both a second TVS diode D2 and a gas discharge tube GT1. The output assembly 158C includes a wire interface board 188A including connectors (e.g., traces) 190, 192, 194, 196, and 198. Trace 190 connects to active flying lead 164, trace 192 connects to active flying lead 166, and trace 194 connects to ground flying lead 168. Traces 196 and 198 are connected to ground trace 194. When output assembly 158C is coupled to encapsulated module 104C, traces 190, 192, 194, 196, and 198 are connected to feedthroughs 138, 140, 142, 184, and 186, respectively. As can be seen in FIG. 5 , in this connection configuration, a first TVS diode D1 is connected between active electrical connector 132A and electrical ground via trace 196, and a second TVS diode D2 is connected between active electrical connector 134A and electrical ground via trace 198. In addition, second electrode 2 of gas-filled discharge tube GT1 is connected to electrical ground via trace 198. Therefore, this connection configuration provides transient protection.

[0030] FIG. 6 is a schematic diagram illustrating a second enclosed module 104C-output assembly 158C configuration in which additional feedthroughs 184 and 186 are routed back to respective lines 132A and 134A for a unit without transient protection. In wire interface board 188B of FIG. 6, trace 196 is routed to trace 190, which is electrically connected to active electrical connector 132A via feedthrough 138. Similarly, trace 198 is routed to trace 192, which is electrically connected to active electrical connector 134A via feedthrough 140. Therefore, no transient protection is provided in this configuration. Except for the routing without transient protection, the remainder of the circuit of FIG. 6 is similar to the circuit of FIG. 5.

[0031] This structure shown in Figures 5 and 6 allows the same sealed module to be used for units with and without transient protection. Customization can be done at the hub, for example, after a few weeks as would have been done with the structure of Figure 4. The additional cost of installing additional modules and the increased annual cost of maintaining those modules is avoided. It should be noted that instead of using different wire interface boards 188A and 188B for the two different connection configurations, a single wire interface board with one or more switches for switching between these two configurations can be used.

[0032] The approval process is also streamlined. Because the concept of Safety Enhancement Zone 1 approval is to reduce the risk of heat and sparks, many common electrical components are not permitted. Removing electrical components from the sealed conduit entry area allows for a seamless and easy analysis for approval.

[0033] This approach gives the end user the flexibility to install the device either as a fire retardant or for added safety. The electronics are not affected by humidity as all electronics have been moved into a sealed package. Very late stage customization is possible. The user can configure the device at commissioning. The device can be reconfigured even after the customer has owned it for some time. For example, a customer can reconfigure the device in the field several years after the initial commissioning.

[0034] The structure of the embodiment can be extended to include other functions, for example: a. The unit is configurable to communicate using HART, Fieldbus, or Modbus protocols; b. The unit is configurable for standard or low power output protocols.

[0035] 7 is a simplified flow diagram of an embodiment of a method 200. At 202, an electromagnetic interference (EMI) protection circuit coupled to a process variable sensor is enclosed in an enclosed module having an electrical connector extending to the exterior. At 204, electronic components of the EMI protection circuit are connected from the exterior of the enclosed module through the electrical connector in a configuration that provides transient protection.

[0036] Although embodiments of the present invention have been described with reference to preferred embodiments, workers skilled in the art will recognize that changes can be made in form and detail without departing from the spirit and scope of the invention.

Claims

1. a process variable sensor; an electromagnetic interference (EMI) protection circuit coupled to the process variable sensor; a sealed module that seals the EMI protection circuit; an electrical connector coupled to the EMI protection circuit within the sealed module and configurable from outside the sealed module such that electronic components of the EMI protection circuit are connected in a configuration that provides transient protection; Equipped with the electrical connector coupled to the EMI protection circuit within the sealed module is configurable from outside the sealed module to connect the electronic components of the EMI protection circuit in a standard configuration without the transient protection. Process variable transmitter.

2. the electrical connector comprises a first electrical connector electrically coupled to a first one of the electronic components of the EMI protection circuit; the first electronic component is further coupled to an active conductor; 10. The process variable transmitter of claim 1.

3. 3. The process variable transmitter of claim 2, wherein the first electrical connector is matable to an electrical ground connector external to the enclosed module so that the first electronic component can provide the transient protection.

4. 3. The process variable transmitter of claim 2, wherein the first electrical connector is matable to the active conductor from outside the enclosed module such that the first electronic component is unable to provide the transient protection.

5. a feedthrough body at a first end of the sealed module; the electrical connector includes a plurality of feedthrough pins extending through the feedthrough body and sealed relative to the feedthrough body; The feedthrough pin is a first active conductor feedthrough pin and a second active conductor feedthrough pin that allow electrical coupling between the first active conductor and the second active conductor inside the sealed module and the first active conductor and the second active conductor outside the sealed module; an electrical ground feedthrough pin that allows electrical coupling between an electrical ground connector inside the sealed module and an electrical ground connector outside the sealed module; a first additional feedthrough pin and a second additional feedthrough pin coupled to different ones of the electronic components of the EMI protection circuit, each of the different ones of the electronic components being further coupled to the first active conductor or the second active conductor in the sealed module; Equipped with 10. The process variable transmitter of claim 1.

6. 6. The process variable transmitter of claim 5, wherein the first additional feedthrough pin and the second additional feedthrough pin are coupled to the electrical ground connector external to the sealed module to enable the transient protection from outside the sealed module.

7. Disable the transient protection. the first additional feedthrough pin is coupled to the first active conductor external to the sealed module; the second additional feedthrough pin is coupled to the second active conductor external to the enclosed module; 6. The process variable transmitter of claim 5.

8. 6. The process variable transmitter of claim 5, wherein the electronic components comprise first and second transient voltage suppression (TVS) diodes and a gas-filled discharge tube.

9. the first TVS diode is coupled to the first active conductor in the hermetic module and to the first additional feedthrough pin in the hermetic module; the second TVS diode is coupled to the second active conductor in the hermetic module and to the second additional feedthrough pin in the hermetic module; the gas-filled discharge tube is coupled to the first active conductor and the second active conductor in the sealed module, and is coupled to the second additional feedthrough pin in the sealed module; 9. The process variable transmitter of claim 8.

10. enclosing an electromagnetic interference (EMI) protection circuit coupled to the process variable sensor in a sealed module having an externally extending electrical connector; connecting electronic components of the EMI protection circuit from outside the sealed module through the electrical connector in a configuration that provides transient protection; connecting the electronic components of the EMI protection circuit from outside the sealed module through the electrical connector in a standard configuration without the transient protection; A method comprising:

11. electrically coupling a first one of the electrical connectors to a first one of the electronic components of the EMI protection circuit; the first electronic component is further coupled to an active conductor; The method of claim 10.

12. 12. The method of claim 11, further comprising: coupling the first electrical connector to an electrical ground connector external to the sealed module so as to provide the transient protection by the first electronic component.

13. 12. The method of claim 11, further comprising electrically coupling the first electrical connector to the active conductor from outside the enclosed module so as to disable the first electronic component from providing the transient protection.

14. a process variable sensor; an electromagnetic interference (EMI) protection circuit coupled to the process variable sensor; an encapsulation module encapsulating the EMI protection circuit, the encapsulation module having a first end including a feedthrough body and a plurality of feedthrough pins extending through the feedthrough body and sealed to the feedthrough body; 1. A process variable transmitter comprising: the feedthrough pin is coupled to the EMI protection circuit within the sealed module and is configurable from outside the sealed module such that electronic components of the EMI protection circuit are connected in a configuration that provides transient protection; The plurality of feedthrough pins include: a first active conductor feedthrough pin and a second active conductor feedthrough pin that allow electrical coupling between the first active conductor and the second active conductor inside the sealed module and the first active conductor and the second active conductor outside the sealed module; an electrical ground feedthrough pin that allows electrical coupling between an electrical ground connector inside the sealed module and an electrical ground connector outside the sealed module; a first additional feedthrough pin and a second additional feedthrough pin coupled to different ones of the electronic components of the EMI protection circuit, each of the different ones of the electronic components being further coupled to the first active conductor or the second active conductor in the sealed module; Including, Process variable transmitter.

15. 15. The process variable transmitter of claim 14, wherein the first additional feedthrough pin and the second additional feedthrough pin are coupled to the electrical ground connector external to the sealed module to enable the transient protection from outside the sealed module.

16. Disable the transient protection. the first additional feedthrough pin is coupled to the first active conductor external to the sealed module; the second additional feedthrough pin is coupled to the second active conductor external to the enclosed module; 15. The process variable transmitter of claim 14.

17. the electronic component comprises first and second transient voltage suppression (TVS) diodes and a gas-filled discharge tube; the first TVS diode is coupled to the first active conductor in the hermetic module and to the first additional feedthrough pin in the hermetic module; the second TVS diode is coupled to the second active conductor in the hermetic module and to the second additional feedthrough pin in the hermetic module; the gas-filled discharge tube is coupled to the first active conductor and the second active conductor in the sealed module and to the second additional feedthrough pin in the sealed module; 15. The process variable transmitter of claim 14.

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