Methods, systems, and devices for monitoring cumulative radiation
Disclosed herein are methods, systems, and devices for monitoring cumulative radiation. In one embodiment, a device includes a photodiode; an integrating capacitor electrically coupled with the photodiode; a voltage discharge switch electrically coupled with the integrating capacitor; and amplifier circuitry electrically coupled with the photodiode and the integrating capacitor. The amplifier circuitry is configured to maintain a substantially zero bias voltage between an anode and a cathode of the photodiode monitoring the cumulative radiation. The integrating capacitor is configured to provide a delta voltage representative of radiation received since the beginning of a charge cycle of the integrating capacitor.
1. A device comprising:
a photodiode;
an integrating capacitor electrically coupled with the photodiode;
a voltage discharge switch electrically coupled with the integrating capacitor;
analog-to-digital circuitry electrically coupled with the integrating capacitor;
temperature compensation circuitry electrically coupled with the analog-to-digital circuitry; and
amplifier circuitry electrically coupled with the photodiode and the integrating capacitor, wherein:
the amplifier circuitry is configured to maintain a substantially zero bias voltage between an anode and a cathode of the photodiode while monitoring cumulative radiation;
the integrating capacitor is configured to provide a delta voltage representative of radiation received during a charge cycle of the integrating capacitor;
the analog-to-digital circuitry is configured for determining when a voltage across the integrating capacitor has crossed a predetermined threshold;
the temperature compensation circuitry is configured for modifying the predetermined threshold; and
the voltage discharge switch is configured for partially discharging the integrating capacitor upon receiving a reset signal.
2. The device of claim 1 , wherein the photodiode is an Aluminum Gallium Nitride based Schottky diode.
3. The device of claim 1 , wherein the device is implemented within at least one of a light dosimeter and a power meter.
4. A device comprising:
a photodiode;
an integrating capacitor electrically coupled with the photodiode;
a voltage discharge switch electrically coupled with the integrating capacitor;
analog-to-digital circuitry electrically coupled with the integrating capacitor;
digital circuitry; and
amplifier circuitry electrically coupled with the photodiode and the integrating capacitor, wherein:
the amplifier circuitry is configured to maintain a substantially zero bias voltage between an anode and a cathode of the photodiode while monitoring cumulative radiation;
the integrating capacitor is configured to provide a delta voltage representative of radiation received during a charge cycle of the integrating capacitor;
the analog-to-digital circuitry is configured for determining when a voltage across the integrating capacitor has crossed a predetermined threshold;
the voltage discharge switch is configured for partially discharging the integrating capacitor upon receiving a reset signal; and
the digital circuitry is configured for providing the reset signal upon the analog-to-digital circuitry determining the voltage across the integrating capacitor has crossed the predetermined threshold.
5. The device of claim 4 , wherein the digital circuitry is configured for providing the reset signal upon determining a predetermined time interval has been exceeded and the voltage across the integrating capacitor has not crossed the predetermined threshold.
6. The device of claim 5 , wherein the digital circuitry is further configured for maintaining a count of a plurality of discharge cycles of the integrating capacitor.
7. The device of claim 6 further comprising a user interface electrically coupled with the digital circuitry, and the user interface is configured for displaying an estimate of a radiation dose received by a surface based on the count of the plurality of discharge cycles of the integrating capacitor.
8. The device of claim 7 , wherein the user interface is configured for receiving a request to reset the count of the plurality of discharge cycles of the integrating capacitor.
9. The device of claim 8 , wherein the user interface comprises:
a liquid crystal display configured for displaying the estimate of the radiation dose received by the surface based on the count of the plurality of discharge cycles of the integrating capacitor; and
a momentary contact switch configured for receiving the request to reset the count of the plurality of discharge cycles of the integrating capacitor.
10. The device of claim 4 , wherein the device is implemented within at least one of a light dosimeter and a power meter.
11. The device of claim 4 , wherein the photodiode is an Aluminum Gallium Nitride based Schottky diode.
12. A device comprising:
a photodiode;
an integrating capacitor electrically coupled with the photodiode;
a voltage discharge switch electrically coupled with the integrating capacitor;
a processor;
a memory electrically coupled with the processor; and
a wireless communication interface electrically coupled with the processor; and
amplifier circuitry electrically coupled with the photodiode and the integrating capacitor, wherein:
the amplifier circuitry is configured to maintain a substantially zero bias voltage between an anode and a cathode of the photodiode while monitoring cumulative radiation;
the integrating capacitor is configured to provide a delta voltage representative of radiation received during a charge cycle of the integrating capacitor;
the wireless communication interface is configured for:
activating from a standby low-power state to an active state upon determining a cumulative radiation dose received by the photodiode has exceeded a predetermined threshold; and
transmitting data associated with the cumulative radiation dose received by the photodiode.
13. The device of claim 12 , wherein wireless interface is compliant to a least one version of a Bluetooth communication protocol.
14. The device of claim 12 , wherein the device is implemented within at least one of a light dosimeter and a power meter.
15. The device of claim 12 , wherein the photodiode is an Aluminum Gallium Nitride based Schottky diode.
16. A device comprising:
a photodiode;
a narrowband optical filter having a passband of at least 250 nanometers to 260 nanometers;
an integrating capacitor electrically coupled with the photodiode;
a voltage discharge switch electrically coupled with the integrating capacitor; and
amplifier circuitry electrically coupled with the photodiode and the integrating capacitor, wherein:
the photodiode is configured for detecting ultraviolet-C radiation;
the amplifier circuitry is configured to maintain a substantially zero bias voltage between an anode and a cathode of the photodiode while monitoring cumulative radiation;
the integrating capacitor is configured to provide a delta voltage representative of radiation received during a charge cycle of the integrating capacitor; and
the narrowband optical filter is integrated with the photodiode.
17. The device of claim 16 , wherein the device is implemented within at least one of a light dosimeter and a power meter.
18. The device of claim 16 , wherein the photodiode is an Aluminum Gallium Nitride based Schottky diode.
19. A device comprising:
a photodiode;
a narrowband optical filter having a passband of at least 220 nanometers to 280 nanometers;
an integrating capacitor electrically coupled with the photodiode;
a voltage discharge switch electrically coupled with the integrating capacitor; and
amplifier circuitry electrically coupled with the photodiode and the integrating capacitor, wherein:
the photodiode is configured for detecting ultraviolet-C radiation;
the amplifier circuitry is configured to maintain a substantially zero bias voltage between an anode and a cathode of the photodiode while monitoring cumulative radiation;
the integrating capacitor is configured to provide a delta voltage representative of radiation received during a charge cycle of the integrating capacitor; and
the narrowband optical filter is integrated with the photodiode.
20. The device of claim 19 , wherein the device is implemented within at least one of a light dosimeter and a power meter.
21. The device of claim 19 , wherein the photodiode is an Aluminum Gallium Nitride based Schottky diode.
22. A method of operating a device for measuring cumulative radiation, the method comprising:
charging an integrating capacitor using a photodiode, wherein a voltage across the integrating capacitor is representative of radiation received during a charge cycle of the integrating capacitor;
maintaining a substantially zero bias voltage between an anode and a cathode of the photodiode using amplifier circuitry electrically coupled with the photodiode and the integrating capacitor;
determining when the voltage across the integrating capacitor has crossed a predetermined threshold;
discharging the voltage across the integrating capacitor using a voltage discharge switch electrically coupled with the integrating capacitor upon receiving a reset signal;
maintaining a count of a plurality of discharge cycles of the integrating capacitor; and
displaying on a user interface an estimate of a radiation dose received by a surface based on the count of the plurality of discharge cycles of the integrating capacitor.