US20010028305A1 - Intrinsically safe sensor and data transmission system - Google Patents
Intrinsically safe sensor and data transmission system Download PDFInfo
- Publication number
- US20010028305A1 US20010028305A1 US09/851,476 US85147601A US2001028305A1 US 20010028305 A1 US20010028305 A1 US 20010028305A1 US 85147601 A US85147601 A US 85147601A US 2001028305 A1 US2001028305 A1 US 2001028305A1
- Authority
- US
- United States
- Prior art keywords
- sensor
- signal
- transmitter
- battery
- monitored
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
Images
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01F—MEASURING VOLUME, VOLUME FLOW, MASS FLOW OR LIQUID LEVEL; METERING BY VOLUME
- G01F23/00—Indicating or measuring liquid level or level of fluent solid material, e.g. indicating in terms of volume or indicating by means of an alarm
- G01F23/80—Arrangements for signal processing
- G01F23/802—Particular electronic circuits for digital processing equipment
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B67—OPENING, CLOSING OR CLEANING BOTTLES, JARS OR SIMILAR CONTAINERS; LIQUID HANDLING
- B67D—DISPENSING, DELIVERING OR TRANSFERRING LIQUIDS, NOT OTHERWISE PROVIDED FOR
- B67D7/00—Apparatus or devices for transferring liquids from bulk storage containers or reservoirs into vehicles or into portable containers, e.g. for retail sale purposes
- B67D7/06—Details or accessories
- B67D7/32—Arrangements of safety or warning devices; Means for preventing unauthorised delivery of liquid
- B67D7/3209—Arrangements of safety or warning devices; Means for preventing unauthorised delivery of liquid relating to spillage or leakage, e.g. spill containments, leak detection
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B67—OPENING, CLOSING OR CLEANING BOTTLES, JARS OR SIMILAR CONTAINERS; LIQUID HANDLING
- B67D—DISPENSING, DELIVERING OR TRANSFERRING LIQUIDS, NOT OTHERWISE PROVIDED FOR
- B67D7/00—Apparatus or devices for transferring liquids from bulk storage containers or reservoirs into vehicles or into portable containers, e.g. for retail sale purposes
- B67D7/06—Details or accessories
- B67D7/36—Arrangements of flow- or pressure-control valves
- B67D7/362—Arrangements of flow- or pressure-control valves combined with over-fill preventing means
Definitions
- the present invention relates generally to the field of remote sensor systems and, more particularly, to an intrinsically safe, wireless, battery-operated sensor system that conserves battery power.
- Level indicators for such tanks typically comprise a tape and pulley apparatus with a float at one end of the tape within the tank and a mechanical level indicator at the other end.
- explosion-proof enclosures are typically constructed of aluminum which is prone to pitting and corrosion, known as exfoliation, particularly when used in marine or coastal environments in which many refining and petrochemical facilities are located.
- sensors In systems in which that system finds applications, sensors typically require some small amount of power to develop a sensed signal, which may then be manipulated into a signal for transmission. Although the amount of power drawn by such sensors is small, it is significant when one is dealing with remote, battery powered sensors which must operate without operator attention over a long period.
- the system of this invention comprises four components: (1) a passive sensor; (2) a transmitter module which includes a microprocessor controller, or microcontroller; (3) a repeater (if required); and (4) a receiver. It provides easy installation, convenient calibration, and very low maintenance. It is specifically designed to provide safe and power-efficient sensor operation where external electrical power and/or alarm signal wiring to a supervised point are not available. Further, it is easily adapted to other systems which include a passive sensor providing an analog signal which is then transmitted by the system of this invention to a central monitor.
- a passive sensor for a specific application is installed.
- a sensor may sense temperature, pressure, flow rate, vibration, torsion or other mechanical stress, level, or other parameters of interest which must be monitored periodically or otherwise on command.
- the sensor typically develops an analog or digital signal, which is coupled through an electrical conductor to the intrinsically safe transmitter.
- the sensor remains unpowered (dormant) until commanded by the microcontroller in the transmitter module to take a reading.
- the command from the microprocessor may be activated by a programmed clock signal within the microprocessor.
- the transmitter module receives a sensed signal from the sensor, it transmits the sensed signal in digital form to a repeater (if necessary) and ultimately to the receiver at the central monitor.
- the sensed signal from the sensor may also include an alarm function by including an alarm switch associated with the sensor.
- the switch When the switch is activated, the transmitter broadcasts an alarm signal to the receiver.
- a relay output at the receiver In the alarm mode of operation, a relay output at the receiver is either opened or closed thus activating the alarm or other device attached to it.
- the relay output may also connect to a control apparatus, such as a signal transmitter to provide for remote operation of such devices as valves.
- the sensor and transmitter package are powered by the same or a secondary battery, such as for example a D cell size 3.6V lithium thionyl chloride battery.
- a supervisory signal may be transmitted by the transmitter module under the control of the microcontroller every 30 seconds or at a selected interval.
- the supervisory signal contains the transmitter identification and battery condition. If the receiving system fails to hear from any of its transmitters, an inactive alarm is issued. Also, low battery alarms are issued before a transmitter's battery dies.
- any type of passive sensing device that provides an analog or digital electrical output signal can be used with this embodiment of the present invention.
- storage vessels may include a magnetostrictive level sensor, such as a liquid level sensing system from Ametek Patriot Sensors in Clawson, Mich.
- magnetostrictive level sensor such as a liquid level sensing system from Ametek Patriot Sensors in Clawson, Mich.
- These devices can be constructed of stainless steel, brass, polypropylene, or other appropriate materials, and are available in a vertical configuration.
- Other passive sensing devices for other parameters to be sensed can also be used in accordance with this invention.
- the system of the present invention provides reliable, low cost, wireless sensor monitoring capability which conserves battery power by activating either the transmitter module or the sensor only when needed. Many applications now require such remote monitoring.
- this system provides continuous, fully supervised protection against conditions which routinely require monitoring. It includes a battery powered transmitter, so it needs no external electrical power at the storage tank.
- the transmitter is intrinsically safe (Class I Division 1 Groups C&D), and requires no FCC licensing. It has low installation and maintenance costs, and the alarms are provided with fail-safe aspects for increased reliability.
- FIG. 1 is an overall schematic diagram of the level monitoring system of this invention.
- FIG. 2 is a detail cross-section view of the transmitter module of this invention.
- FIG. 3 is a schematic diagram of the invention adapted for use with a passive sensor.
- FIG. 1 shows an exemplary level monitoring system 10 of this invention. It should be understood that the system 10 is equally applicable to any remote parameter which may require monitoring functions, so long as the parameter is sensed by a sensor, and the sensor develops an analog or digital signal for further manipulation by the system 10 .
- the system may also include the alarm features of our parent application, U.S. application Ser. No. 09/541,353.
- the system shown in FIG. 1 monitors the fluid level 12 in a storage tank 14 .
- the fluid level is detected by a passive level sensor 16 which moves vertically with fluid level 12 .
- the level sensor 16 is coupled by a wire 20 to the interior of a mast 22 , which supports a transmitter module 24 .
- the passive level sensor requires electrical power in order to be activated to give a level indication.
- the provision of electrical power is microprocessor activated, as described below with regard to FIGS. 2 and 3.
- the transmitter module 24 also remains dormant until activated by microcontroller command.
- the transmitter module 24 transmits a signal, either to an intermediate repeater 26 , if required, or directly to a receiver 28 .
- the repeater 26 is required if the distance from the transmitter module 24 to the receiver 28 is too great to transmit directly to the receiver 28 , which may be located in a distant control room.
- the receiver 28 may be dedicated to a specific transmitter module 24 , or the system can be configured so that the repeater 26 boosts signals from a number of transmitters and other repeaters.
- the repeater 26 is preferably mounted within a weatherproof nonmetallic (NEMA 4X) enclosure that can be purged for use in hazardous areas. It uses AC power, with an internal backup battery included to continue operation through power outages.
- the repeater 26 may have a specified range, for example of up to 3 km (line of sight). Additional repeaters can be used for greater distances or to clear obstructions.
- the receiver 28 may operate as a stand-alone receiver (discrete) or with a computer interface (serial). Discrete receivers may have an LED display indicating exact tank location, fluid level, or the value of any other sensed parameter, such as pressure in psig, temperature in degrees Fahrenheit, or variation from a specified norm or limit, etc. If the system operates with a computer interface, the receiver 28 can monitor hundreds of similar transmitter modules 24 . Receivers 28 may only “listen” for transmitters and repeaters programmed to them.
- a central station 30 labeled in FIG. 1 with the functions of control, display, and alarm, provides means for displaying the value of the signal from the sensor.
- a display may comprise a separate gauge, but preferably comprises a selectable readout display on a computer monitor.
- the receiver 28 may also provide relay outputs which can be used to sound an alarm, shut off a pump, close a valve, activate a telephone auto-dialer, or operate almost any other device.
- system of this invention is also adaptable to other applications where a passive switch can sense an out of specification condition.
- a passive switch can sense an out of specification condition.
- certain systems require proper operation within a band of pressures, and such a system may include a passive switch for each of the upper and lower pressure settings.
- Such an application and others are within the scope and spirit of the present invention.
- the transmitter module and the sensing device are intrinsically safe. No spark producing components are exposed to volatile gases, and such gases are retained entirely within the tank 14 , unlike known systems.
- the receiver 28 may be dedicated to many such sensor monitoring systems, and may passively monitor all of the sensor monitoring systems assigned to it. Further, as shown in FIG. 1, the system is independent of external power requirements, and it is independent of communication wiring from the transmitter module 24 to the receiver 28 .
- the transmitter module 24 includes a sealed outer shell 32 , such as fiberglass or other durable, weather resistant material.
- the transmitter module 24 mounts onto the mast 22 , such as for example with a cavity 34 to receive the top of the mast, and may be secured with a set screw 36 .
- a multi-strand electrical conductor 38 Also through the mast is a multi-strand electrical conductor 38 , which is coupled at the tank 14 to the level sensor 16 .
- the conductor 38 is directed into a sealed chamber 40 , which is sealed at the bottom with a bottom wall 42 and at the top with a top cap 44 .
- the top of the chamber 40 is further sealed with an O-ring seal 46 .
- the conductor 38 penetrates the bottom wall 42 through a stuffing tube, or is otherwise potted to seal the penetration with the wall 42 .
- the chamber 40 includes a battery 48 , a transmitter 50 , and a microcontroller 68 ′.
- the battery is preferably a lithium thionyl chloride battery, available from Tadiran in Port Washington, N.Y., selected because of its high power density and long life.
- the system may also include a solar charging system (not shown) in order to extend the useful life of the battery even further between replacement cycles.
- the battery is mounted into the transmitter module 24 with battery clips, and is electrically coupled to the transmitter 50 with wires 52 and a battery connector 54 .
- the battery 48 , transmitter 50 , and microcontroller 68 ′ are preferably assembled as a unit onto a backbone 56 , for ease of installation and maintenance.
- the battery 48 may also provide power to the sensor by way of the electrical conductor 38 through the wall 42 , if desired.
- the transmitter 50 is self-contained, intrinsically safe, and very reliable. Once the level sensor 16 is activated, the transmitter module 24 sends a radio frequency signal, which includes a unique identifying code to distinguish the transmitter from any other transmitter included in the system 10 . It should be noted that the microcontroller 68 ′ may include buffer memory so that the sensed signal need not be transmitted immediately.
- the onboard battery 48 (which also powers the sensors) has a 2-3 year life, and provides fully supervised operation.
- a supervisory signal is transmitted by the transmitter 50 periodically, for example every 30 seconds, which contains the ID Code of the specific transmitter module 24 and battery condition. If the receiver 28 or the central station 30 the fails to hear from any of its associated transmitters, such as transmitter module 24 , an inactive alarm is issued. Also, low battery alarms may be issued about 30 days before a transmitter's battery dies.
- the transmitter 50 may comprise a 900 MHz spread spectrum device that contains an onboard processor and non-volatile ROM.
- the transmitter 50 is preferably awakened from its dormant state by its own onboard processor, but it may alternatively be controlled by the microcontroller 68 ′.
- the transmitter 50 is enclosed in a fiberglass housing, and contains the components shown in FIG. 3.
- the transmitter module 24 includes the sealed outer shell 32 as previously described.
- a passive sensor 60 which may detect temperature, pressure, flow rate, level, or any other appropriate parameter which may vary over time, is placed where it is exposed to the parameter.
- the transmitter module 24 may also be dedicated to more than one such sensor, such as for example a sensor 60 ′.
- the sensor 60 or 60 ′ provides an analog signal over a signal line 62 to an analog to digital (A/D) converter 64 .
- the A/D converter digitizes the analog signal, and conducts that digital signal over a communication line 66 to a microprocessor 68 .
- the A/D converter is bypassed.
- the microprocessor is programmed to monitor the incoming digital signal for a limit condition or a band of specific values.
- the digitized signal is processed by the microprocessor 68 into a transmitter signal over a communication line 70 , and the transmitter signal may be periodically transmitted by the transmitter module 24 to periodically monitor the predetermined parameter, or the transmitter may only be activated if an out of specification condition develops.
- the sensors 60 and 60 ′ may also be provided with command lines 72 and 72 ′, respectively.
- the microprocessor 68 issues a command to turn on the sensors; otherwise the sensors remain de-energized, in order to conserve energy.
- the command signal to energize the sensors originates from a timed periodic programmed command from the microprocessor 68 .
Abstract
Description
- This application is a Continuation In Part of U.S. patent application Ser. No. 09/541,353; filed Mar. 31, 2000, which will issue on May 8, 2001 as U.S. Pat. No. 6,229,448; which claims the benefit of U.S. Provisional Patent Application Ser. No. 60/128,868; filed Apr. 12, 1999.
- The present invention relates generally to the field of remote sensor systems and, more particularly, to an intrinsically safe, wireless, battery-operated sensor system that conserves battery power.
- Industry and safety standards require that liquid storage tanks of the type located on petroleum tank farms be given periodic checks to determine the liquid level of each tank. Level indicators for such tanks typically comprise a tape and pulley apparatus with a float at one end of the tape within the tank and a mechanical level indicator at the other end.
- This typical arrangement was improved on by Clarkson, U.S. Pat. No. 4,459,584, to include a transmitter for remote monitoring of liquid level, but the Clarkson system still required the use of the old tape and pulley system to monitor liquid level. This system suffered all of the common problems with the tape and pulley system in that such a system may mechanically jam, thereby disabling the movement of the float. Further, a large volume of volatile gases fills the conduit enclosing the tape and pulley, since this system is open to the tank. This feature alone presents a significant safety hazard. Further, the Clarkson system provides no means for calibration of the level detector, since it relies upon the old tape and pulley system.
- We began the development of the present invention with a level monitoring and alarm system sold under the trademark Fillcheck®. This system included a transmitter that was mounted in an off-the-shelf NEMA-7 explosion-proof enclosure so as to enable it to be used in the electrically hazardous environments associated with petroleum storage tanks, pipelines, oil refineries, petrochemical plants, and fuel terminals. This type of mounting solved the problems described with regard to Clarkson, but it brought about certain shortcomings, such as the attenuation of the level signal. Mounting the transmitter and its antenna inside the explosion-proof enclosure significantly reduced the system's effective range. In this system, the explosion-proof transmitter had to be aimed toward its receiver or repeater for optimum performance. Further, that system was expensive, and the transmitter had to be equipped with a safety barrier so as to permit its connection to an external level switch, which added to system cost. That system was also heavy, in that explosion-proof enclosures are quite massive and add significantly to shipping and handling costs. Finally, explosion-proof enclosures are typically constructed of aluminum which is prone to pitting and corrosion, known as exfoliation, particularly when used in marine or coastal environments in which many refining and petrochemical facilities are located.
- The recognition of these drawbacks of the Fillcheck® system led to the development of the system which is described and claimed in our U.S. patent application Ser. No. 09/541,353; filed Mar. 31, 2000; which will issue on May 8, 2001 as U.S. Pat. No. 6,229,448; the parent application of the present application. In that system, we disclosed an intrinsically safe transmitter which maybe used generally for sending digital signals derived from any analog sensor, including a sensor for temperature, pressure, flow rate, etc., as well as the tank level sensor for which the original system was specifically designed. The original impetus for the that system was over-fill protection for storage tanks in hazardous environments, and has proven to be successful.
- In systems in which that system finds applications, sensors typically require some small amount of power to develop a sensed signal, which may then be manipulated into a signal for transmission. Although the amount of power drawn by such sensors is small, it is significant when one is dealing with remote, battery powered sensors which must operate without operator attention over a long period.
- Thus, there remains a need for a sensor monitoring system which is intrinsically safe and operates only intermittently in order to conserve the precious resource of battery power. The present invention addresses this need in the art.
- The system of this invention comprises four components: (1) a passive sensor; (2) a transmitter module which includes a microprocessor controller, or microcontroller; (3) a repeater (if required); and (4) a receiver. It provides easy installation, convenient calibration, and very low maintenance. It is specifically designed to provide safe and power-efficient sensor operation where external electrical power and/or alarm signal wiring to a supervised point are not available. Further, it is easily adapted to other systems which include a passive sensor providing an analog signal which is then transmitted by the system of this invention to a central monitor.
- In a preferred embodiment of the invention, a passive sensor for a specific application is installed. Such a sensor may sense temperature, pressure, flow rate, vibration, torsion or other mechanical stress, level, or other parameters of interest which must be monitored periodically or otherwise on command. The sensor typically develops an analog or digital signal, which is coupled through an electrical conductor to the intrinsically safe transmitter. The sensor remains unpowered (dormant) until commanded by the microcontroller in the transmitter module to take a reading. The command from the microprocessor may be activated by a programmed clock signal within the microprocessor. When the transmitter module receives a sensed signal from the sensor, it transmits the sensed signal in digital form to a repeater (if necessary) and ultimately to the receiver at the central monitor.
- The sensed signal from the sensor may also include an alarm function by including an alarm switch associated with the sensor. When the switch is activated, the transmitter broadcasts an alarm signal to the receiver. In the alarm mode of operation, a relay output at the receiver is either opened or closed thus activating the alarm or other device attached to it. The relay output may also connect to a control apparatus, such as a signal transmitter to provide for remote operation of such devices as valves.
- The sensor and transmitter package are powered by the same or a secondary battery, such as for example a D cell size 3.6V lithium thionyl chloride battery. During non-alarm conditions, a supervisory signal may be transmitted by the transmitter module under the control of the microcontroller every 30 seconds or at a selected interval. The supervisory signal contains the transmitter identification and battery condition. If the receiving system fails to hear from any of its transmitters, an inactive alarm is issued. Also, low battery alarms are issued before a transmitter's battery dies.
- Any type of passive sensing device that provides an analog or digital electrical output signal can be used with this embodiment of the present invention. For example, storage vessels may include a magnetostrictive level sensor, such as a liquid level sensing system from Ametek Patriot Sensors in Clawson, Mich. These devices can be constructed of stainless steel, brass, polypropylene, or other appropriate materials, and are available in a vertical configuration. Other passive sensing devices for other parameters to be sensed can also be used in accordance with this invention.
- The system of the present invention provides reliable, low cost, wireless sensor monitoring capability which conserves battery power by activating either the transmitter module or the sensor only when needed. Many applications now require such remote monitoring. Thus, this system provides continuous, fully supervised protection against conditions which routinely require monitoring. It includes a battery powered transmitter, so it needs no external electrical power at the storage tank. The transmitter is intrinsically safe (Class I Division 1 Groups C&D), and requires no FCC licensing. It has low installation and maintenance costs, and the alarms are provided with fail-safe aspects for increased reliability.
- FIG. 1 is an overall schematic diagram of the level monitoring system of this invention.
- FIG. 2 is a detail cross-section view of the transmitter module of this invention.
- FIG. 3 is a schematic diagram of the invention adapted for use with a passive sensor.
- FIG. 1 shows an exemplary
level monitoring system 10 of this invention. It should be understood that thesystem 10 is equally applicable to any remote parameter which may require monitoring functions, so long as the parameter is sensed by a sensor, and the sensor develops an analog or digital signal for further manipulation by thesystem 10. The system may also include the alarm features of our parent application, U.S. application Ser. No. 09/541,353. - The system shown in FIG. 1 monitors the
fluid level 12 in astorage tank 14. The fluid level is detected by apassive level sensor 16 which moves vertically withfluid level 12. Thelevel sensor 16 is coupled by awire 20 to the interior of amast 22, which supports atransmitter module 24. - The passive level sensor requires electrical power in order to be activated to give a level indication. The provision of electrical power is microprocessor activated, as described below with regard to FIGS. 2 and 3. The
transmitter module 24 also remains dormant until activated by microcontroller command. - Upon activation, the
transmitter module 24 transmits a signal, either to anintermediate repeater 26, if required, or directly to areceiver 28. Therepeater 26 is required if the distance from thetransmitter module 24 to thereceiver 28 is too great to transmit directly to thereceiver 28, which may be located in a distant control room. In a preferred embodiment, thereceiver 28 may be dedicated to aspecific transmitter module 24, or the system can be configured so that therepeater 26 boosts signals from a number of transmitters and other repeaters. Therepeater 26 is preferably mounted within a weatherproof nonmetallic (NEMA 4X) enclosure that can be purged for use in hazardous areas. It uses AC power, with an internal backup battery included to continue operation through power outages. Therepeater 26 may have a specified range, for example of up to 3 km (line of sight). Additional repeaters can be used for greater distances or to clear obstructions. - The
receiver 28 may operate as a stand-alone receiver (discrete) or with a computer interface (serial). Discrete receivers may have an LED display indicating exact tank location, fluid level, or the value of any other sensed parameter, such as pressure in psig, temperature in degrees Fahrenheit, or variation from a specified norm or limit, etc. If the system operates with a computer interface, thereceiver 28 can monitor hundreds ofsimilar transmitter modules 24.Receivers 28 may only “listen” for transmitters and repeaters programmed to them. - Once the
receiver 28 senses a received signal from thetransmitter module 24, acentral station 30, labeled in FIG. 1 with the functions of control, display, and alarm, provides means for displaying the value of the signal from the sensor. Such a display may comprise a separate gauge, but preferably comprises a selectable readout display on a computer monitor. Thereceiver 28 may also provide relay outputs which can be used to sound an alarm, shut off a pump, close a valve, activate a telephone auto-dialer, or operate almost any other device. - It should be noted that the system of this invention is also adaptable to other applications where a passive switch can sense an out of specification condition. For example, certain systems require proper operation within a band of pressures, and such a system may include a passive switch for each of the upper and lower pressure settings. Such an application and others are within the scope and spirit of the present invention.
- It is particularly noteworthy in the system shown in FIG. 1 that the transmitter module and the sensing device are intrinsically safe. No spark producing components are exposed to volatile gases, and such gases are retained entirely within the
tank 14, unlike known systems. It should also be noted that thereceiver 28 may be dedicated to many such sensor monitoring systems, and may passively monitor all of the sensor monitoring systems assigned to it. Further, as shown in FIG. 1, the system is independent of external power requirements, and it is independent of communication wiring from thetransmitter module 24 to thereceiver 28. - Referring to FIG. 2, the
transmitter module 24 includes a sealedouter shell 32, such as fiberglass or other durable, weather resistant material. Thetransmitter module 24 mounts onto themast 22, such as for example with acavity 34 to receive the top of the mast, and may be secured with aset screw 36. Also through the mast is a multi-strandelectrical conductor 38, which is coupled at thetank 14 to thelevel sensor 16. - The
conductor 38 is directed into a sealedchamber 40, which is sealed at the bottom with abottom wall 42 and at the top with atop cap 44. The top of thechamber 40 is further sealed with an O-ring seal 46. Theconductor 38 penetrates thebottom wall 42 through a stuffing tube, or is otherwise potted to seal the penetration with thewall 42. - The
chamber 40 includes abattery 48, atransmitter 50, and amicrocontroller 68′. The battery is preferably a lithium thionyl chloride battery, available from Tadiran in Port Washington, N.Y., selected because of its high power density and long life. The system may also include a solar charging system (not shown) in order to extend the useful life of the battery even further between replacement cycles. The battery is mounted into thetransmitter module 24 with battery clips, and is electrically coupled to thetransmitter 50 withwires 52 and abattery connector 54. Thebattery 48,transmitter 50, andmicrocontroller 68′ are preferably assembled as a unit onto abackbone 56, for ease of installation and maintenance. Thebattery 48 may also provide power to the sensor by way of theelectrical conductor 38 through thewall 42, if desired. - The
transmitter 50 is self-contained, intrinsically safe, and very reliable. Once thelevel sensor 16 is activated, thetransmitter module 24 sends a radio frequency signal, which includes a unique identifying code to distinguish the transmitter from any other transmitter included in thesystem 10. It should be noted that themicrocontroller 68′ may include buffer memory so that the sensed signal need not be transmitted immediately. The onboard battery 48 (which also powers the sensors) has a 2-3 year life, and provides fully supervised operation. A supervisory signal is transmitted by thetransmitter 50 periodically, for example every 30 seconds, which contains the ID Code of thespecific transmitter module 24 and battery condition. If thereceiver 28 or thecentral station 30 the fails to hear from any of its associated transmitters, such astransmitter module 24, an inactive alarm is issued. Also, low battery alarms may be issued about 30 days before a transmitter's battery dies. - The
transmitter 50 may comprise a 900 MHz spread spectrum device that contains an onboard processor and non-volatile ROM. Thetransmitter 50 is preferably awakened from its dormant state by its own onboard processor, but it may alternatively be controlled by themicrocontroller 68′. Thetransmitter 50 is enclosed in a fiberglass housing, and contains the components shown in FIG. 3. - Referring now to FIG. 3, an embodiment including the features of the invention is disclosed. The
transmitter module 24 includes the sealedouter shell 32 as previously described. In this case, apassive sensor 60, which may detect temperature, pressure, flow rate, level, or any other appropriate parameter which may vary over time, is placed where it is exposed to the parameter. Thetransmitter module 24 may also be dedicated to more than one such sensor, such as for example asensor 60′. Thesensor signal line 62 to an analog to digital (A/D)converter 64. The A/D converter digitizes the analog signal, and conducts that digital signal over acommunication line 66 to amicroprocessor 68. If thesensor microprocessor 68 into a transmitter signal over acommunication line 70, and the transmitter signal may be periodically transmitted by thetransmitter module 24 to periodically monitor the predetermined parameter, or the transmitter may only be activated if an out of specification condition develops. - The
sensors command lines microprocessor 68 issues a command to turn on the sensors; otherwise the sensors remain de-energized, in order to conserve energy. The command signal to energize the sensors originates from a timed periodic programmed command from themicroprocessor 68. - The principles, preferred embodiment, and mode of operation of the present invention have been described in the foregoing specification. This invention is not to be construed as limited to the particular forms disclosed, since these are regarded as illustrative rather than restrictive. Moreover, variations and changes maybe made by those skilled in the art without departing from the spirit of the invention.
Claims (18)
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US09/851,476 US6369715B2 (en) | 1999-04-12 | 2001-05-08 | Intrinsically safe sensor and data transmission system |
Applications Claiming Priority (3)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US12886899P | 1999-04-12 | 1999-04-12 | |
US09/541,353 US6229448B1 (en) | 1999-04-12 | 2000-03-31 | Intrinsically safe fluid tank overfill protection system |
US09/851,476 US6369715B2 (en) | 1999-04-12 | 2001-05-08 | Intrinsically safe sensor and data transmission system |
Related Parent Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US09/541,353 Continuation-In-Part US6229448B1 (en) | 1999-04-12 | 2000-03-31 | Intrinsically safe fluid tank overfill protection system |
Publications (2)
Publication Number | Publication Date |
---|---|
US20010028305A1 true US20010028305A1 (en) | 2001-10-11 |
US6369715B2 US6369715B2 (en) | 2002-04-09 |
Family
ID=46257737
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US09/851,476 Expired - Lifetime US6369715B2 (en) | 1999-04-12 | 2001-05-08 | Intrinsically safe sensor and data transmission system |
Country Status (1)
Country | Link |
---|---|
US (1) | US6369715B2 (en) |
Cited By (10)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO2004047043A2 (en) * | 2002-11-15 | 2004-06-03 | Vega Grieshaber Kg | Wireless communication |
US20060077612A1 (en) * | 2004-10-05 | 2006-04-13 | Ajay Kothari | Wireless communication using an intrinsically safe design for use in a hazardous area |
WO2006052895A1 (en) * | 2004-11-08 | 2006-05-18 | Crane Nuclear, Inc. | System and method for monitoring equipment |
WO2006065704A1 (en) * | 2004-12-13 | 2006-06-22 | Veeder-Root Company | Wireless probe system and method for a fueling environment |
US20090013107A1 (en) * | 2003-09-23 | 2009-01-08 | Detlev Wittmer | Method for Safe Data Transmission Between an Intrinsically Safe Sensor and a Non-Intrinsically Safe Evaluation Unit |
US20100026518A1 (en) * | 2008-06-26 | 2010-02-04 | Endres + Hauser Flowtec Ag | Measuring system having a sensor module and a transmitter module |
WO2011076263A1 (en) * | 2009-12-22 | 2011-06-30 | Abb As | Wireless sensor device and method for wirelessly communicating a sensed physical parameter |
WO2013006624A1 (en) * | 2011-07-07 | 2013-01-10 | General Equipment And Manufacturing Company, Inc., D/B/A Topworx, Inc. | Wireless monitoring systems for use with pressure safety devices |
US20160305800A1 (en) * | 2013-12-17 | 2016-10-20 | Endress + Hauser Flowtec Ag | Vortex Flow Measuring Device |
WO2021150272A1 (en) * | 2020-01-24 | 2021-07-29 | Appleton Grp Llc | Luminaire as an intrinsically safe power source |
Families Citing this family (31)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US6794991B2 (en) * | 1999-06-15 | 2004-09-21 | Gastronics′ Inc. | Monitoring method |
US7061398B2 (en) * | 1999-08-16 | 2006-06-13 | Bs&B Safety Systems Limited | Two-way wide area telemetry |
US20030025612A1 (en) * | 1999-08-16 | 2003-02-06 | Holmes John K. | Wireless end device |
US6967589B1 (en) * | 2000-08-11 | 2005-11-22 | Oleumtech Corporation | Gas/oil well monitoring system |
US6760464B2 (en) * | 2000-10-11 | 2004-07-06 | Digimarc Corporation | Halftone watermarking and related applications |
AU2003225271A1 (en) * | 2002-04-30 | 2003-11-17 | Chevron U.S.A. Inc. | Temporary wireless sensor network system |
CA2433314C (en) * | 2002-08-23 | 2007-03-27 | Firemaster Oilfield Services Inc. | Apparatus system and method for gas well site monitoring |
US7096522B2 (en) * | 2002-12-06 | 2006-08-29 | Hirtriter R Eric | Bath overflow alarm suitable for different installation arrangements |
US7140257B2 (en) * | 2002-12-10 | 2006-11-28 | Ashcroft Inc. | Wireless transmitting pressure measurement device |
US6998998B2 (en) * | 2003-02-05 | 2006-02-14 | Schlumberger Technology Corporation | High speed hazardous area communication with safety barriers |
WO2004094971A1 (en) * | 2003-03-27 | 2004-11-04 | Dresser, Inc. | Temperature measurement device |
US7165461B2 (en) * | 2003-03-27 | 2007-01-23 | Ashcroft, Inc. | Pressure gauge having dual function movement plate |
US7937216B2 (en) | 2004-04-03 | 2011-05-03 | Humphrey Richard L | System for monitoring propane or other consumable liquid in remotely located storage tanks |
US20060243347A1 (en) * | 2005-04-02 | 2006-11-02 | Humphrey Richard L | System for monitoring propane or other consumable liquid in remotely located storage tanks |
US7295919B2 (en) * | 2004-04-03 | 2007-11-13 | Nas Corp. | System for delivering propane or other consumable liquid to remotely located storage tanks |
US20050235749A1 (en) * | 2004-04-27 | 2005-10-27 | Jerry Morris | Liquid level monitoring system |
US7441569B2 (en) * | 2005-04-28 | 2008-10-28 | Robertshaw Controls Company | Will call wireless tank level monitoring system |
US7278293B2 (en) * | 2005-06-16 | 2007-10-09 | Rosemount, Inc. | Submersible probe |
US20100001867A1 (en) * | 2007-12-28 | 2010-01-07 | Matthew Rodrigue | Device, system and method for monitoring tank content levels |
US20090243863A1 (en) * | 2008-03-31 | 2009-10-01 | Robertshaw Controls Company | Intrinsically Safe Cellular Tank Monitor For Liquified Gas and Cryogenic Liquids |
US8567242B1 (en) * | 2010-03-11 | 2013-10-29 | S.J. Electro Systems, Inc. | Pressure sensor venting system |
WO2012058770A1 (en) | 2010-11-05 | 2012-05-10 | Steven Slupsky | Wireless sensor device |
IL209390A0 (en) * | 2010-11-17 | 2011-01-31 | High Check Control Ltd | Sensor system |
WO2015137997A1 (en) | 2013-03-15 | 2015-09-17 | Compology, Inc. | System and method for waste management |
US9506795B2 (en) | 2014-04-07 | 2016-11-29 | Silversmith, Inc. | Wireless tank level monitoring |
CA2891800A1 (en) * | 2014-05-15 | 2015-11-15 | Arthur E. Colvin, Jr. | Wireless fluid sensor |
US20150348391A1 (en) * | 2014-05-30 | 2015-12-03 | Derrick Ernest Hilton | Two part digital intelligence unit for gas cylinders |
US10480765B2 (en) | 2015-06-08 | 2019-11-19 | Eaton Intelligent Power Limited | Integration of sensor components with light fixtures in hazardous environments |
US10943356B2 (en) | 2018-12-12 | 2021-03-09 | Compology, Inc. | Method and system for fill level determination |
US10798522B1 (en) | 2019-04-11 | 2020-10-06 | Compology, Inc. | Method and system for container location analysis |
US11172325B1 (en) | 2019-05-01 | 2021-11-09 | Compology, Inc. | Method and system for location measurement analysis |
Family Cites Families (9)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4369437A (en) | 1981-03-16 | 1983-01-18 | Thompson Jr Robert E | Security and alarm apparatus |
US4459584A (en) | 1981-12-21 | 1984-07-10 | Clarkson Marvin R | Automatic liquid level indicator and alarm system |
US5363093A (en) | 1992-08-11 | 1994-11-08 | Tanknology Corporation International | Method and apparatus for continuous tank monitoring |
US5610324A (en) | 1993-11-08 | 1997-03-11 | Fugitive Emissions Detection Devices, Inc. | Fugitive emissions indicating device |
US5642097A (en) | 1995-02-21 | 1997-06-24 | Martel; Phillip G. | Remotely readable fuel tank indicator system |
US5708424A (en) | 1996-08-19 | 1998-01-13 | Orlando; Vincent | Wireless remote fuel gauge |
US5762118A (en) | 1996-11-05 | 1998-06-09 | I C E M Enterprises Inc. | Apparatus and method for the cordless remote control of a filling function of a mobile vehicle |
US5946084A (en) | 1998-01-26 | 1999-08-31 | Innovative Sensor Solutions, Ltd. | Hemispherical double reflection optical sensor |
US6229448B1 (en) * | 1999-04-12 | 2001-05-08 | Innovative Sensor Solutions, Ltd. | Intrinsically safe fluid tank overfill protection system |
-
2001
- 2001-05-08 US US09/851,476 patent/US6369715B2/en not_active Expired - Lifetime
Cited By (25)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO2004047043A3 (en) * | 2002-11-15 | 2004-07-08 | Grieshaber Vega Kg | Wireless communication |
WO2004047043A2 (en) * | 2002-11-15 | 2004-06-03 | Vega Grieshaber Kg | Wireless communication |
US8102278B2 (en) | 2002-11-15 | 2012-01-24 | Vega Grieshaber Kg | Wireless communication |
US20090013107A1 (en) * | 2003-09-23 | 2009-01-08 | Detlev Wittmer | Method for Safe Data Transmission Between an Intrinsically Safe Sensor and a Non-Intrinsically Safe Evaluation Unit |
US20060077612A1 (en) * | 2004-10-05 | 2006-04-13 | Ajay Kothari | Wireless communication using an intrinsically safe design for use in a hazardous area |
US7312716B2 (en) | 2004-10-05 | 2007-12-25 | Azonix | Wireless communication using an intrinsically safe design for use in a hazardous area |
WO2006052895A1 (en) * | 2004-11-08 | 2006-05-18 | Crane Nuclear, Inc. | System and method for monitoring equipment |
US20060146469A1 (en) * | 2004-11-08 | 2006-07-06 | Heagerty David Q | System and method for monitoring equipment |
GB2438060A (en) * | 2004-11-08 | 2007-11-14 | Crane Nuclear Inc | System and method for monitoring equipment |
US8872651B2 (en) | 2004-12-13 | 2014-10-28 | Veeder-Root Company | Wireless probe system and method for a fueling environment |
WO2006065704A1 (en) * | 2004-12-13 | 2006-06-22 | Veeder-Root Company | Wireless probe system and method for a fueling environment |
US20090256700A1 (en) * | 2004-12-13 | 2009-10-15 | Veeder-Root Company | Wireless Probe System and Method For a Fueling Environment |
US7561040B2 (en) | 2004-12-13 | 2009-07-14 | Veeder-Root Company | Wireless probe system and method for a fueling environment |
US20060139169A1 (en) * | 2004-12-13 | 2006-06-29 | Veeder-Root Company | Wireless probe system and method for a fueling environment |
US20100026518A1 (en) * | 2008-06-26 | 2010-02-04 | Endres + Hauser Flowtec Ag | Measuring system having a sensor module and a transmitter module |
AU2009357245B2 (en) * | 2009-12-22 | 2015-01-22 | Abb As | Wireless sensor device and method for wirelessly communicating a sensed physical parameter |
WO2011076263A1 (en) * | 2009-12-22 | 2011-06-30 | Abb As | Wireless sensor device and method for wirelessly communicating a sensed physical parameter |
EA021718B1 (en) * | 2009-12-22 | 2015-08-31 | Абб Ас | Wireless sensor device and method for wirelessly communicating a sensed physical parameter |
US9578398B2 (en) | 2009-12-22 | 2017-02-21 | Abb As | Wireless sensor device and method for wirelessly communicating a sensed physical parameter |
CN103718121A (en) * | 2011-07-07 | 2014-04-09 | 通用设备和制造公司 | Wireless monitoring systems for use with pressure safety devices |
JP2014523037A (en) * | 2011-07-07 | 2014-09-08 | ジェネラル イクイップメント アンド マニュファクチャリング カンパニー, インコーポレイテッド, ディー/ビー/エー トップワークス, インコーポレイテッド | Wireless monitoring system for use with pressure safety devices |
WO2013006624A1 (en) * | 2011-07-07 | 2013-01-10 | General Equipment And Manufacturing Company, Inc., D/B/A Topworx, Inc. | Wireless monitoring systems for use with pressure safety devices |
US20160305800A1 (en) * | 2013-12-17 | 2016-10-20 | Endress + Hauser Flowtec Ag | Vortex Flow Measuring Device |
WO2021150272A1 (en) * | 2020-01-24 | 2021-07-29 | Appleton Grp Llc | Luminaire as an intrinsically safe power source |
US11553571B2 (en) | 2020-01-24 | 2023-01-10 | Appleton Grp Llc | Luminaire as an intrinsically safe power source |
Also Published As
Publication number | Publication date |
---|---|
US6369715B2 (en) | 2002-04-09 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
US6369715B2 (en) | Intrinsically safe sensor and data transmission system | |
US6229448B1 (en) | Intrinsically safe fluid tank overfill protection system | |
US6338283B1 (en) | Self-contained electronic system for monitoring purgers, valves and installations in real time | |
US7562570B2 (en) | Ultrasonic oil/water tank level monitor having wireless transmission means | |
US6967589B1 (en) | Gas/oil well monitoring system | |
CN102279245B (en) | Integrated acousto-optic warning gas detector | |
US7221282B1 (en) | Wireless wastewater system monitoring apparatus and method of use | |
CA2285838C (en) | Monitoring system with power supply built therein | |
US20040098218A1 (en) | System for acquiring data from a facility and method | |
WO2013070131A1 (en) | Monitoring of floating roof tank | |
KR101662050B1 (en) | Leakage detecting apparatus and leakage detecting system using the same | |
US20220044545A1 (en) | Air-sea buoy monitoring system towards mid-latitude ocean | |
CN105910764B (en) | Transformer oil storage capsules break detection method | |
CN113374946B (en) | Safety processing system for liquefied natural gas conveying hose | |
WO2020214064A1 (en) | Method and device for the automatic wireless monitoring of a liquid level | |
US6542827B1 (en) | Well tending method and apparatus | |
CN112419677A (en) | Combustible gas detection alarm system | |
CN218825798U (en) | Full-automatic oil gas pipeline stress monitoring system | |
EP1215471B1 (en) | Liquid level sensing system | |
CN209910899U (en) | Liquid immersion type leakage monitoring device for power equipment | |
CN208672497U (en) | Oil-immersed transformer insulation ag(e)ing detection system | |
EP1045228A1 (en) | System measuring the contents of tanks via a transmitter/receiver of brief data by radio waves at short/long distance | |
CN220366861U (en) | Intelligent monitoring system and intelligent well for heat supply | |
CN213121900U (en) | Pipe network water quality monitoring device | |
CN211347201U (en) | Pipe network pressure real-time detection system |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
AS | Assignment |
Owner name: INNOVATIVE SENSOR SOLUTIONS, LTD., TEXAS Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:BENNETT, JR., PAUL R.;TAYLOR, III, J. LAWRENCE;REEL/FRAME:012132/0175 Effective date: 20010507 |
|
STCF | Information on status: patent grant |
Free format text: PATENTED CASE |
|
FEPP | Fee payment procedure |
Free format text: PAT HOLDER CLAIMS SMALL ENTITY STATUS, ENTITY STATUS SET TO SMALL (ORIGINAL EVENT CODE: LTOS); ENTITY STATUS OF PATENT OWNER: SMALL ENTITY |
|
REFU | Refund |
Free format text: REFUND - PAYMENT OF MAINTENANCE FEE, 4TH YEAR, LARGE ENTITY (ORIGINAL EVENT CODE: R1551); ENTITY STATUS OF PATENT OWNER: SMALL ENTITY |
|
FEPP | Fee payment procedure |
Free format text: PAYOR NUMBER ASSIGNED (ORIGINAL EVENT CODE: ASPN); ENTITY STATUS OF PATENT OWNER: SMALL ENTITY |
|
AS | Assignment |
Owner name: OMNTEC MFG., INC., NEW YORK Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:INNOVATIVE SENSOR SOLUTIONS, LTD.;REEL/FRAME:016926/0294 Effective date: 20050609 |
|
FPAY | Fee payment |
Year of fee payment: 4 |
|
REMI | Maintenance fee reminder mailed | ||
AS | Assignment |
Owner name: OMNTEC MFG. INC, NEW YORK Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:INNOVATIVE SENSOR SOLUTIONS, LTD;REEL/FRAME:017537/0738 Effective date: 20050609 |
|
FPAY | Fee payment |
Year of fee payment: 8 |
|
FPAY | Fee payment |
Year of fee payment: 12 |