Multi-sense environmental monitoring device and method

• US 9,575,043 B2
• Filed: 04/01/2015
• Issued: 02/21/2017
• Est. Priority Date: 06/25/2010
• Status: Active Grant

• Current Assignee: Industrial Scientific Corporation (Fortive Corp.)
• Original Assignee: Industrial Scientific Corporation (Fortive Corp.)
• Inventors: Arunachalam, Raghu
• Primary Examiner(s): Fan, Hongmin
• Application Number:
  US14/676,443
• Publication Number:
  US 20150204830A1
• Time in Patent Office: 692 Days
• US Class Current: 1/1
• CPC Class Codes: G01N 33/0006 Calibrating gas analysers
• CPC Class Codes: G01N 33/0031 comprising two or more sensors, e.g. a sensor array
• CPC Class Codes: G01N 33/0063 using a threshold to release an alarm or displaying means
• CPC Class Codes: G08B 21/14 Toxic gas alarms G08B21/16 takes precedence
• CPC Class Codes: G08B 21/16 Combustible gas alarms
• CPC Class Codes: G08B 21/182 Level alarms, e.g. alarms responsive to variables exceeding a threshold
• CPC Class Codes: G08B 29/16 Security signalling or alarm systems, e.g. redundant systems
• CPC Class Codes: G08B 29/24 Self-calibration, e.g. compensating for environmental drift or ageing of components
• CPC Class Codes: G08B 29/26 by updating and storing reference thresholds
• CPC Class Codes: G08B 5/22 using electric transmission; using electromagnetic transmission

Abstract

An environmental monitoring device for detecting and warning users of unhealthy levels of a given substance is disclosed having more than one sensor for each substance to be detected. Each sensor for each substance detected may be positioned in more than one plane or surface on the device. The device may be capable of auto or self calibration. Methods for reading substance levels and auto calibrating are also disclosed.

Claims

1. A monitoring device for monitoring substances, the monitoring device comprising:

a plurality of sensors, each of at least two sensors of the plurality of sensors being configured to detect a same substance separately from all other sensors of the monitoring device and to generate an output signal in response to a detection of the same substance;

a processing unit operably coupled to the at least two sensors, the processing unit being configured to;

receive each of the output signals from the at least two sensors,

determine a detection signal for the same substance based on the output signals, and

generate a calibration action responsive to at least two of the output signals deviating by a threshold amount, the calibration action comprising performing self-calibration by adjusting a gain of a sensor according to the relationship;

sensorGain^new=sensorGain^old+0.1*[max(sensorReading1, sensorReading2)]/[min (sensorReading1, sensorReading2)]; and

a display operably coupled to the processing unit, the display being configured to show a detection condition for the same substance in accordance with the detection signal.

2. The monitoring device of claim 1, wherein the processing unit is configured to determine a display reading based on a respective concentration detected by each of the plurality of sensors.

3. The monitoring device of claim 1, further comprising a user interface configured to provide control signals to said processing unit, the user interface comprising at least one of a button, key, or touch screen.

4. The monitoring device of claim 1, wherein the processing unit is configured to determine a difference between signals from at least a portion of the plurality of sensors and to generate a sensor fail signal responsive to the difference being outside of a threshold amount.

5. A monitoring device for monitoring substances, the monitoring device comprising:

at least two sensors configured to detect a same substance and to generate an output signal in response to a detection of the same substance; and

a processing unit operably coupled to the at least two sensors, the processing unit being configured to;

receive each of the output signals from the at least two sensors, determine a weight of each of the at least two sensors configured to

indicate a reliability of each of the at least two sensors,

determine an aggregate substance concentration reading by aggregating the output signals from the at least two sensors biased toward output signals from sensors indicated as being more reliable based on the weights, and

generate a calibration action responsive to at least two of the output signals deviating by a threshold amount, the calibration action comprising performing self-calibration, wherein the calibration action comprises self-calibration by adjusting a gain of a sensor according to the relationship;

sensorGain^new=sensorGain^old+0.1*[max(sensorReading1, sensorReading2)]/[min (sensorReading1, sensorReading2)].

6. The monitoring device of claim 5, wherein the weight is determined based on at least one of gain, span reserve, historic calibration performance, and historic bump test performance.

7. The monitoring device of claim 5, further comprising a display operably coupled to the processing unit, the display being configured to show a detection condition for the same substance in accordance with the detection signal.

8. The monitoring device of claim 5, further comprising a user interface configured to provide control signals to said processing unit, the user interface comprising at least one of a button, key, or touch screen.