Real-time air monitoring with multiple sensing modes
Embodiments of a gas detector with a first gas sensor having a first gas specificity and a first response time and a second gas sensor having a second gas specificity and a second response time. The first gas specificity is different than the second gas specificity, the first response time is different than the second response time, or both the first gas specificity and the first response time are different than the second gas specificity and the second response time. A readout and analysis circuit is coupled to the first and second gas sensors to read and analyze data from the first and second gas sensors, and a control circuit is coupled to the readout and analysis circuit and to the first and second gas sensors to execute logic that operates the first gas sensor, the second gas sensor, or both the first and second gas sensors.
1. A gas detector assembly comprising:
a first gas detection system including a first sample conditioner fluidly coupled to a first gas sensor, the first gas sensor having a first gas specificity and a first response time;
a second gas detection system including a second sample conditioner fluidly coupled to a second gas sensor, the second gas sensor having a second gas specificity and a second response time, wherein the first gas specificity is different than the second gas specificity, the first response time is different than the second response time, or both the first gas specificity and the first response time are different than the second gas specificity and the second response time;
a readout and analysis circuit coupled to the first and second gas sensors to read and analyze data from the first and second gas sensors; and
a control circuit coupled to the readout and analysis circuit, to the first and second sample conditioners, and to the first and second gas sensors, wherein the control circuit can execute logic that:
activates the first sample conditioner and the first gas sensor, and
if the result from the first gas sensor meets detection criteria, activates sample collection by the second sample conditioner.
2. The gas detector assembly of claim 1 wherein the first gas sensor is a fast-response low-specificity sensor and the second gas sensor is a fast-response partial-specificity sensor.
3. The gas detector assembly of claim 1 wherein the first gas sensor is a fast-response partial-specificity sensor and the second gas sensor is a slow-response high-specificity sensor.
4. The gas detector assembly of claim 1 , further comprising a third gas detection system including a third sample conditioner fluidly coupled to a third gas sensor, the third gas sensor having a third gas specificity and a third response time and being coupled to the control circuit.
5. The gas detector assembly of claim 4 wherein:
the first gas sensor is a fast-response low-specificity sensor,
the second gas sensor is a fast-response partial-specificity sensor, and
the third gas sensor is a slow-response high-specificity sensor.
6. The gas detector assembly of claim 4 wherein the first, second, and third gas detection systems are coupled to a gas sampling manifold with single or multiple inlets for sampling from multiple locations.
7. The gas detector assembly of claim 4 wherein if the result from the second gas sensor meets detection criteria, the control circuit activates sample collection by the third sample conditioner.
8. The gas detector assembly of claim 7 wherein the control circuit further activates the third gas sensor after activating the third sample conditioner.
9. The gas detector assembly of claim 8 wherein the control circuit returns to operation of the first gas detection system or the second gas detection system when the third gas sensor has completed its sensing.
10. The gas detector assembly of claim 4 wherein the control circuit can select the second gas detection system or the third gas detection system, depending on whether the result obtained from the first gas sensor meets criteria for operating the second gas detection system or meets criteria for activating the third gas detection system.
11. The gas detector assembly of claim 10 wherein the control circuit returns to operation of the first gas detection system when the second gas sensor has completed its sensing or returns to operation of the second gas detection system when the third gas sensor has completed its sensing.
12. The gas detector assembly of claim 1 wherein the control circuit further activates the second gas sensor after activating the second sample conditioner.
13. The gas detector assembly of claim 12 wherein the control circuit returns to operation of the first gas detection system when the second gas sensor has completed its sensing.
14. The gas detector assembly of claim 4 wherein the first sample conditioner, the second sample conditioner, the third sample conditioner, or all three, include an external pre-concentrator.
15. A gas analysis process comprising:
receiving a gas sample at a gas detector assembly including:
a first gas detection system including a first sample conditioner fluidly coupled to a first gas sensor, the first gas sensor having a first gas specificity and a first response time;
a second gas detection system including a second sample conditioner fluidly coupled to a second gas sensor, the second gas sensor having a second gas specificity and a second response time, wherein the first gas specificity is different than the second gas specificity, the first response time is different than the second response time, or both the first gas specificity and the first response time are different than the second gas specificity and the second response time;
a readout and analysis circuit coupled to the first and second gas sensors to read and analyze data from the first and second gas sensors; and
a control circuit coupled to the readout and analysis circuit, to the first and second sample conditioners, and to the first and second gas sensors, wherein the control circuit can execute logic that:
activates the first sample conditioner and the first gas sensor, and
if the result from the first gas sensor meets detection criteria, activates sample collection by the second sample conditioner; and
analyzing a sample collected by the second sample conditioner.
16. The process of claim 15 wherein the first gas sensor is a fast-response low-specificity sensor and the second gas sensor is a fast-response partial-specificity sensor.
17. The process of claim 15 wherein the first gas sensor is a fast-response partial-specificity sensor and the second gas sensor is a slow-response high-specificity sensor.
18. The process of claim 15 wherein the gas detector assembly further comprises a third gas detection system including a third sample conditioner fluidly coupled to a third gas sensor, the third gas sensor having a third gas specificity and a third response time and being coupled to the control circuit.
19. The process of claim 18 wherein:
the first gas sensor is a fast-response low-specificity sensor,
the second gas sensor is a fast-response partial-specificity sensor, and
the third gas sensor is a slow-response high-specificity sensor.
20. The process of claim 18 wherein the first, second, and third gas detection systems are coupled to a gas sampling manifold with single or multiple inlets for sampling from multiple locations.
21. The process of claim 18 wherein if the result from the second gas sensor meets detection criteria, the control circuit activates sample collection by the third sample conditioner.
22. The process of claim 21 , further comprising analyzing a sample collected by the third sample conditioner.
23. The process of claim 22 wherein analyzing the sample collected by the third sample conditioner comprises activating the third gas sensor and directing the sample collected by the third sample conditioner to the third gas sensor.
24. The process of claim 23 wherein the control circuit returns to operation of the first gas detection system or the second gas detection system when the third gas sensor has completed its sensing.
25. The process of claim 18 wherein the control circuit can select the second gas detection system or the third gas detection system, depending on whether the result obtained from the first gas sensor meets criteria for operating the second gas detection system or meets criteria for activating the third gas detection system.
26. The process of claim 25 wherein the control circuit returns to operation of the first gas detection system when the second gas sensor has completed its sensing or returns to operation of the second gas detection system when the third gas sensor has completed its sensing.
27. The process of claim 18 wherein the first sample conditioner, the second sample conditioner, the third sample conditioner, or all three, include an external pre-concentrator.
28. The process of claim 15 wherein analyzing the sample collected by the second sample conditioner comprises activating the second gas sensor and directing the sample collected by the second sample conditioner to the second gas sensor.
29. The process of claim 28 wherein the control circuit returns to operation of the first gas detection system when the second gas sensor has completed its sensing.