Determining failure of an ultraviolet sensor

Methods, devices, and systems for determining failure of an ultraviolet (UV) sensor are described herein. One device includes a memory, and a processor configured to execute executable instructions stored in the memory to reduce an excitation voltage of a UV sensor until no conduction occurs in the UV sensor, increase, upon no conduction occurring in the UV sensor, the excitation voltage of the UV sensor until a conduction event occurs, compare the excitation voltage at which the conduction event occurs to a reference voltage, and determine whether the UV sensor has failed based on the comparison.

TECHNICAL FIELD

The present disclosure relates to methods, devices, and systems for determining failure of ultraviolet (UV) sensors.

BACKGROUND

Ultraviolet (UV) sensors are designed to detect the presence of UV radiation. For example, UV sensors may be utilized to detect the presence of radiation in the spectral range of approximately 10 nm to 400 nm.

UV sensors may be useful in many different product applications. For example, UV sensors may be useful in detecting the presence of a flame in a burner. Detecting the presence of a flame inside a burner can help a user (e.g., technician and/or maintenance personnel) safely operate and/or service the burner. For instance, if no flame is present in the burner, the user may shut the burner down to prevent unburned fuel from accumulating inside of the burner.

UV sensors may be damaged or wear out over time. For example, the fill-gas composition within the UV sensor may change over time. Other examples can include damage to the spacing of electrodes inside the UV sensor, or surface defects on the electrodes. Damage to a UV sensor can lead to dangerous operating conditions for a product application containing a UV sensor. Therefore, it is important to know if a UV sensor has become damaged or failed.

DETAILED DESCRIPTION

Methods, devices, and systems for determining failure of an ultraviolet (UV) sensor are described herein. For example, one or more embodiments include a memory, and a processor configured to execute executable instructions stored in the memory to reduce an excitation voltage of a UV sensor until no conduction occurs in the UV sensor, increase, upon no conduction occurring in the UV sensor, the excitation voltage of the UV sensor until a conduction event occurs, compare the excitation voltage at which the conduction event occurs to a reference voltage, and determine whether the UV sensor has failed based on the comparison.

Determining the failure of a UV sensor, in accordance with the present disclosure, can allow a user (e.g., technician and/or maintenance personnel) to easily determine whether a UV sensor has become damaged and/or has failed. Such simple determination of whether a UV sensor has failed can lead to safer operation of product applications utilizing UV sensors. For example, a failed UV sensor may be indicated to a user before a dangerous condition arises in the operation of the product containing the failed UV sensor. The failed UV sensor can then be replaced without incident.

The figures herein follow a numbering convention in which the first digit or digits correspond to the drawing figure number and the remaining digits identify an element or component in the drawing. Similar elements or components between different figures may be identified by the use of similar digits. For example,104may reference element “04” inFIG. 1, and a similar element may be reference as404inFIG. 4.

As used herein, “a” or “a number of” something can refer to one or more such things. For example, “a number of UV events” can refer to one or more UV events.

FIG. 1illustrates a system100for determining failure of an ultraviolet (UV) sensor, in accordance with one or more embodiments of the present disclosure. As shown inFIG. 1, the system100includes a controller104and a UV sensor106. Additionally, system100comprises a product application102that can include a burner101, a shut-off valve103, a burner management system105, and a flame107.

The UV sensor106can be a sensor designed to detect the presence of ultraviolet (UV) radiation emissions (e.g., UV events). UV radiation can include electromagnetic radiation with a wavelength that can range from 10 nanometers (nm) to 400 nm. For example, UV sensor106can be configured to detect the presence of UV radiation within a wavelength range of 10 nm to 400 nm.

Although UV sensor106is described as having a detection range from 10 nm to 400 nm, embodiments of the present disclosure are not so limited. For example, UV sensor106can have a detection range that is narrower than 10 nm to 400 nm (e.g., 180 nm to 260 nm).

The detection of UV emissions by UV sensor106can be referred to as a UV event. For example, UV sensor106detecting an instance of UV emission (e.g., electromagnetic radiation) within the wavelength range of 10 nm to 400 nm (e.g., 200 nm) can be a UV event. As another example, UV sensor106detecting a number of instances of UV emission can be a number of UV events.

UV sensor106can include a UV tube with electrodes located within. Further, UV sensor106can include a composition of fill-gas inside the UV tube, as will be further described herein (e.g., in connection withFIG. 3).

As shown inFIG. 1, product application102can include a burner101, a shut-off valve103, a burner management system105, and a flame107. For example, product application102can be a burner system that is utilizing UV sensor106to detect the presence of flame107from burner101. That is, UV sensor106can be used to detect the presence of flame107by detecting UV emissions (e.g., UV events) emitted from flame107.

In some embodiments, burner101can be a fuel-air or fuel-oxygen burner to produce (e.g., generate) a flame107. For example, burner101can be used to produce flame107to generate heat for use in residential and/or commercial hot water boiler/heater applications. However, embodiments of the present disclosure are not so limited. For example, burner101can be used for any other suitable application.

In some embodiments, shut-off valve103can be a fuel safety shut-off valve for burner101. For example, if UV sensor106does not detect any UV events (e.g., does not detect the presence of flame107), shut-off valve103can turn off the flow of fuel into burner101, preventing the buildup of unburnt fuel in burner101. As another example, if UV sensor106is determined to have failed, shut-off valve103can turn off the flow of fuel into burner101.

In some embodiments, burner management system105can control various aspects of the operation of burner101. For example, burner management system105can change the firing rate of burner101to produce a more intense flame107or a less intense flame107based on the required heat output of burner101. As another example, burner management system105can turn burner101on and off.

In some embodiments, flame107can be a flame produced by burner101that emits UV radiation that can be sensed by UV sensor106. For example, flame107can produce electromagnetic radiation in the wavelength defined by UV (e.g., 10 nm to 400 nm) that can be sensed by UV sensor106.

The use of UV sensor106in product application102can render the operation of product application102safer. For example, if UV sensor106is utilized in a product application102such as a burner, UV sensor106can determine that a flame within the burner has been extinguished (e.g., quenched) due to UV events not being detected by UV sensor106. A user (e.g., technician and/or maintenance personnel) can then shut down the burner in response to UV sensor106not detecting UV events to stop the flow of fuel into the burner when there is no flame to prevent the buildup of unburnt fuel and/or other associated problems (e.g., explosions).

Controller104can determine whether UV sensor106has failed. For example, controller104can reduce an excitation voltage of UV sensor106until no conduction occurs in UV sensor106. Upon no conduction occurring in UV sensor106, controller104can increase the excitation voltage of UV sensor106until a conduction event occurs. Controller104can then compare the excitation voltage at which the conduction event occurs to a reference voltage, and determine, based on the comparison, whether UV sensor106has failed. The process by which controller104can determine whether UV sensor106has failed will be further described herein (e.g., in connection withFIG. 2).

A conduction event can be defined by a first instance of conduction in UV sensor106as the excitation voltage of UV sensor106is increased from a non-conducting state when UV sensor106is in the presence of UV emissions. For example, as the excitation voltage of UV sensor106is increased, a conduction event occurs at the moment UV sensor106first begins to conduct (e.g., UV sensor106first begins to detect UV emissions).

A reference voltage, as used herein, is an excitation voltage at which UV sensor106is expected to detect a conduction event when UV sensor106is properly functioning. As the excitation voltage of UV sensor106is increased from a state where no UV events occur (e.g., no conduction in UV sensor106), the conduction event can be expected to occur at a reference (e.g., a known) voltage. For example, as the excitation voltage is increased from 0 volts to 6 volts, the conduction event can be expected to occur at a reference voltage of 3 volts.

As another example, the excitation voltage of UV sensor106is decreased from a state where UV events are occurring (e.g., conduction in UV sensor106) to a state where no UV events occur (e.g., no conduction in UV sensor106). Conduction in UV sensor106can be expected to stop occurring when the excitation voltage of UV sensor106is reduced beyond a reference (e.g., a known) voltage.

Although the reference voltage is described as being a specific voltage, embodiments of the present disclosure are not so limited. For example, the reference voltage can be a known range of reference voltages. For instance, the reference voltage range can be between 2 and 4 volts. The reference voltage range can be an inclusive voltage range or an exclusive voltage range. Additionally, the reference voltage range can be a manufacturer's specification.

The conduction event can occur within the known range of reference voltages. For example, as an excitation voltage of UV sensor106is increased from 0 volts to 6 volts, the conduction event can be expected to happen between a reference voltage range of 2 volts to 4 volts (e.g., conduction event can happen at 3 volts).

Increasing the excitation voltage of UV sensor106from a state where no UV events occur (e.g., no conduction in UV sensor106) until a conduction event occurs, and decreasing the excitation voltage of UV sensor106from a state where UV events are occurring (e.g., conduction in UV sensor106) to a state where no UV events occur (e.g., no conduction in UV sensor106) can bound the range of operation of UV sensor106. This bounded range of operation of UV sensor106can be compared to acceptable limits of the range of operation of UV sensor106.

In some embodiments, the reference voltage can be specified by a manufacturer of UV sensor106. For example, controller104may include (e.g., store) a reference voltage specified by the manufacturer of UV sensor106. The reference voltage can be specified by the manufacturer as a result of product testing that produces a reliable reference voltage at which UV sensor106can be expected to detect a conduction event.

In some embodiments, the reference voltage and/or reference voltage range of UV sensor106can vary based on the construction of UV sensor106. For example, changes in the position of electrodes, the composition of the fill gas, and/or the pressure within the UV tube of UV sensor106can result in a reference voltage and/or reference voltage range that differs from a UV sensor with different electrode positioning, fill gas composition, and/or pressure within the UV tube.

FIG. 2is a flow chart of a method208for determining failure of a UV sensor (e.g., UV sensor106and306described in connection withFIGS. 1 and 3, respectively), in accordance with one or more embodiments of the present disclosure. Method208can be performed by, for example, controllers104and404, as described in connection withFIGS. 1 and 4, respectively.

At block210of method208, the controller can reduce an excitation voltage of a UV sensor until no conduction occurs in the UV sensor. As used herein, conduction occurring in the UV sensor indicates a sufficient excitation voltage being applied to the UV sensor such that the UV sensor is detecting UV events. For example, the controller can supply an excitation voltage to the UV sensor such that when the UV sensor is detecting UV events (e.g., UV emissions), conduction is occurring in the UV sensor.

As the controller reduces the excitation voltage of the UV sensor, conduction will cease to occur in the UV sensor. For example, the UV sensor will not detect UV events at an excitation voltage that has been reduced beyond the reference voltage. As another example, the UV sensor will not detect UV events at an excitation voltage that has been reduced beyond a reference voltage range.

At block212of method208, the controller can increase the excitation voltage of the UV sensor until a conduction event occurs. For example, once no conduction occurs in the UV sensor, the controller can increase the excitation voltage of the UV sensor until the UV sensor detects a conduction event. The conduction event can correspond to a first instance of conduction occurring in the UV sensor (e.g., a first UV event) as the excitation voltage is increased.

The controller can determine the excitation voltage at which the conduction event occurs. For example, as the excitation voltage of the UV sensor is increased, the excitation voltage (e.g., 3 volts) at which the conduction event occurs can be recorded.

At block214of method208, the controller can compare the excitation voltage at which the conduction event occurs to a reference voltage. For example, if the conduction event occurs at an excitation voltage of 3 volts, the controller can compare the excitation voltage (e.g., 3 volts) to a reference voltage of 4 volts.

In some embodiments, the reference voltage can be a range of reference voltages. For example, the reference voltage range can be a range of voltages at which a conduction event can be expected to happen. For instance, the reference voltage range can be a range of 2-4 volts. If the conduction event occurs at an excitation voltage of 3 volts, the controller can compare the excitation voltage of the conduction event (e.g., 3 volts) to the reference voltage range of 2-4 volts.

At block216of method208, the controller can determine whether the UV sensor has failed based on the comparison of the excitation voltage of the conduction event to the reference voltage. For example, the controller can compare an excitation voltage of a conduction event (e.g., 3 volts) to a reference voltage (e.g., 4 volts) to determine whether the UV sensor has failed.

The UV sensor can be determined to have failed upon the excitation voltage at which the conduction event occurs and the reference voltage being different. For example, if the excitation voltage of the conduction event is 3 volts and the reference voltage is 4 volts, the controller can determine that the UV sensor has failed based on the excitation voltage of the conduction event being different than the reference voltage. As another example, if the excitation voltage of the conduction event is 5 volts and the reference voltage is 4 volts, the controller can determine that the UV sensor has failed based on the excitation voltage of the conduction event being different than the reference voltage.

In embodiments in which the reference voltage is a range of reference voltages, the UV sensor can be determined to have failed upon the excitation voltage at which a conduction event occurs being outside the reference voltage range. For example, if the excitation voltage of the conduction event is 5 volts and the range of reference voltages is 2-4 volts, the controller can determine that the UV sensor has failed based on the excitation voltage of the conduction event being outside of the range of reference voltages.

That is, the UV sensor can be determined to have failed based on the excitation voltage at which the conduction event occurs being higher or lower than the reference voltage or the reference voltage range. For example, the conduction event can occur at an excitation voltage that is higher or lower than a reference voltage to result in the UV sensor having failed. As another example, the conduction event can occur at an excitation voltage that is higher or lower than a reference voltage range to result in the UV sensor having failed.

In some embodiments, the controller can determine the UV sensor has not failed. For example, if the conduction event occurs at an excitation voltage of 4 volts, the controller can compare the excitation voltage of the conduction event (e.g., 4 volts) to a reference voltage of 4 volts and determine that the UV sensor has not failed based on the excitation voltage of the conduction event being the same as the reference voltage. As an additional example, if the conduction event occurs at an excitation voltage of 3 volts, the controller can compare the excitation voltage of the conduction event (e.g., 3 volts) to a reference voltage range of 2-4 volts and determine that the UV sensor has not failed based on the excitation voltage of the conduction event being within the range of reference voltages.

At block218of method208, the controller can lock out the UV sensor if the UV sensor has been determined to have failed (e.g., software lockout condition). For example, once the controller has determined the UV sensor has failed, the controller can lock out the UV sensor via software so that a user (e.g., technician and/or maintenance personnel) may safely replace the UV sensor. As another example, the controller can lock out the product application the UV sensor is being used in so that a user may safely perform maintenance (e.g., replace the UV sensor) or perform other tasks associated with the product application.

A lock out condition (e.g., software lockout condition), as used herein, is a process by which a piece of equipment (e.g., UV sensor and/or product application) is secured against accidental energization during repairs and/or maintenance. A software lock out condition can be utilized to prevent a user from being harmed by equipment that may unexpectedly start while the user is performing tasks on the equipment.

Method208can be performed while the UV sensor is detecting UV events. For example, the UV sensor can be checked for failure while the UV sensor is operating within a product application (e.g., product application102described in connection withFIG. 1). Further, the UV sensor can be checked while the product application containing the UV sensor is operating. For instance, the UV sensor can be checked for failure without having to take a product application offline.

Method208can be performed upon the excitation voltage at which the conduction event occurs being the same as the reference voltage. For example, the method can be repeated as long as the excitation voltage of the conduction event is the same as the reference voltage. For instance, the method can be repeated for as long as the UV sensor has not been indicated to have failed.

In some embodiments, the results of the method can be subject to additional signal processing. For example, the excitation voltage at which the conduction event occurs can be logged, and an average excitation voltage over a sample size of measurements of conduction events can be compared to a reference voltage and/or reference voltage range. As another example, the results can be normalized and/or totaled for other data analyses.

In some embodiments, the method208can be repeated at a particular frequency. For example, the method can be repeated more than once per second (e.g., 3 times per second). However, embodiments of the present disclosure are not so limited. For example, the method can be repeated once per second or less than once per second.

In some embodiments, the frequency of the repeating of method208can be more than once per second if the product application containing the UV sensor is operating at a high capacity. For example, if the UV sensor is being utilized in a product application such as a burner, the method208can be repeated more often when the burner is being heavily utilized (e.g., more intense flame).

In some embodiments, the frequency of the repeating of method208can be less than or equal to once per second if the product application containing the UV sensor is not operating at a full capacity. For example, if the UV sensor is being utilized in a product application such as a burner, the method208can be repeated less often when the burner is not being heavily utilized (e.g., less intense flame).

In some embodiments, the frequency of the repeating of method208can be increased as the UV sensor ages. For example, as a UV sensor gets older and becomes worn with use from operation in a product application, the UV sensor can be more likely subject to a failure than a new UV sensor. Therefore, the method208to check for UV sensor failure can be repeated more often on an older UV sensor than on a newer UV sensor.

The method208can be concluded upon the UV sensor being determined to have failed. For example, upon the excitation voltage of a conduction event being different than a reference voltage or the excitation voltage being outside of a range of reference voltages, the method208can be concluded and the controller can render the UV sensor and/or product application in a lock out condition.

FIG. 3is an illustration of a portion of a UV sensor306, in accordance with one or more embodiments of the present disclosure. UV sensor306can be, for example, UV sensor106previously described in connection withFIG. 1. As shown inFIG. 3, a UV sensor306can include a UV tube324, electrodes328-1and328-2, and a fill-gas composition326.

UV tube324, as used herein, can be a housing that includes a fill-gas composition326and electrodes328-1and328-2. Additionally, UV tube324can be a housing formed from material to allow the penetration of UV emissions322into UV tube324.

UV tube324can include fill-gas composition326. Fill-gas composition326can be a composition of one or more gases to allow for the detection of UV events by UV sensor306. Additionally, fill-gas composition326can be a volume to induce a certain pressure within UV tube324to allow for detection of UV events by UV sensor306.

UV tube324can include electrodes328-1and328-2. For example, electrodes328-1and328-2can be placed within UV tube324at a specified distance so as to allow for detection of UV events by UV sensor306.

Signs of a UV sensor that is aging can include reduced pressure of fill-gas composition326or a change in the spacing of electrodes324. For example, a change in the spacing of electrodes324can lead to a change in the excitation voltage at a conduction event, which can lead to UV sensor failure.

FIG. 4is a schematic block diagram of a controller404for determining failure of a UV sensor, in accordance with one or more embodiments of the present disclosure. Controller404can be, for example, controller104previously described in connection withFIG. 1. For example, controller404can include a memory432and a processor430configured to determine failure of a UV sensor in accordance with the present disclosure. Further, controller404can include an adjustable voltage supply434and sense circuitry436.

Adjustable voltage supply434can supply an excitation voltage to a UV sensor (e.g., UV sensor106and306described in connection withFIGS. 1 and 3, respectively). For example, adjustable voltage supply434can supply a range of excitation voltages to a UV sensor (e.g., 0 volts to 12 volts).

Sense circuitry436can be circuitry that can sense UV emission. For example, sense circuitry436can determine a UV event has occurred when a UV sensor is in the presence of UV emissions.

The memory432can be any type of storage medium that can be accessed by the processor430to perform various examples of the present disclosure. For example, the memory432can be a non-transitory computer readable medium having computer readable instructions (e.g., computer program instructions) stored thereon that are executable by the processor430to compare an excitation voltage at which a conduction event occurs to a reference voltage to determine whether a UV sensor has failed. That is, processor430can execute the executable instructions stored in memory432to compare an excitation voltage at which a conduction event occurs to a reference voltage to determine whether a UV sensor has failed.

The memory432can be volatile or nonvolatile memory. The memory432can also be removable (e.g., portable) memory, or non-removable (e.g., internal) memory. For example, the memory432can be random access memory (RAM) (e.g., dynamic random access memory (DRAM) and/or phase change random access memory (PCRAM)), read-only memory (ROM) (e.g., electrically erasable programmable read-only memory (EEPROM) and/or compact-disc read-only memory (CD-ROM)), flash memory, a laser disc, a digital versatile disc (DVD) or other optical storage, and/or a magnetic medium such as magnetic cassettes, tapes, or disks, among other types of memory.

Further, although memory432is illustrated as being located within controller404, embodiments of the present disclosure are not so limited. For example, memory432can also be located internal to another computing resource (e.g., enabling computer readable instructions to be downloaded over the Internet or another wired or wireless connection).

As used herein, “logic” is an alternative or additional processing resource to execute the actions and/or functions, etc., described herein, which includes hardware (e.g., various forms of transistor logic, application specific integrated circuits (ASICs), etc.), as opposed to computer executable instructions (e.g., software, firmware, etc.) stored in memory and executable by a processor. It is presumed that logic similarly executes instructions for purposes of the embodiments of the present disclosure.