Transportable gas detector unit having mounted gas sources for gas sensor testing and calibration

1. A transportable gas detector unit comprising:

a controller and a battery contained within the transportable gas detector unit;

one or more source inlets for connection to one or more gas sources, said gas sources mounted on the transportable gas detector unit by mounting points on the transportable gas detector unit, the mounting points being configured to rigidly hold the gas sources in place when the transportable gas detector unit is moved;

a chamber comprising a gas-permeable portion to allow gaseous communication with an outside environment and one or more source outlets configured to receive gas from the one or more source inlets;

a gas sensor in communication with the controller and positioned within the chamber;

a flow switch controlled by the controller, the flow switch configured to allow the received gas to be introduced directly into the chamber via the one or more source outlets; and

a wireless transceiver configured to enable communication between the controller and a remote computer;

wherein the transportable gas detector unit is configured to:

in a detection mode, detect gases entering the chamber through the gas-permeable portion from the outside environment; and

in a test mode, introduce gas via the one or more source outlets and test that the gas sensor is detecting the introduced gas; and

wherein the transportable gas detector unit is moveable and includes a handle.

2. The transportable gas detector unit according to claim 1 , wherein the transportable gas detector unit further comprises a pressure sensor configured to measure a gas pressure within the chamber when gas is being introduced into the chamber and to transmit an alert in response to the gas pressure exceeding a predetermined threshold.

3. The transportable gas detector unit according to claim 1 , wherein the transportable gas detector unit is further configured to switch between the test mode and the detection mode in response to receiving a command remotely via the wireless transceiver.

4. The transportable gas detector unit according to claim 1 , wherein the transportable gas detector unit is further configured to switch autonomously between the test mode and the detection mode.

5. The transportable gas detector unit according to claim 1 , wherein the gas-permeable portion further comprises a mesh screen with mesh openings of less than 150 microns.

6. The transportable gas detector unit according to claim 1 , wherein the handle has a handle switch which is activated when the transportable gas detector unit is lifted; and wherein the transportable gas detector unit is further configured to transmit location information to the remote computer in response to the handle being released.

7. The transportable gas detector unit according to claim 1 , wherein the transportable gas detector unit is further configured to:

perform a series of bump tests, each bump test comprising introducing a gas into the chamber and measuring a sensor response until a predetermined response threshold is reached;

measure trends in the measured sensor response for each of the series of bump tests over time; and

determine when a calibration is due based on the measured trends.

8. The transportable gas detector unit according to claim 1 , wherein the transportable gas detector unit is further configured to:

perform a series of bump tests, each bump test comprising introducing a gas into the chamber and measuring a sensor response until a predetermined response threshold is reached;

measure trends in the measured sensor response for each of the series of bump tests over time; and

determine when a sensor is nearing its end of life.

9. The transportable gas detector unit according to claim 1 , wherein the transportable gas detector unit is further configured to:

introduce a baseline gas into the chamber;

measure a response of a sensor which is insensitive to the introduced baseline gas; and

determine a baseline for said sensor based on the measured response to the introduced baseline gas.

10. The transportable gas detector unit according to claim 1 , wherein the transportable gas detector unit further comprises a motion sensor.

11. The transportable gas detector unit according to claim 1 , wherein the transportable gas detector unit further comprises a wind sensor.

12. The transportable gas detector unit according to claim 1 , wherein the transportable gas detector unit further comprises a microphone.

13. The transportable gas detector unit according to claim 1 , wherein the transportable gas detector unit further comprises a microphone and a speaker configured to sound an audio alarm when activated by the controller, the microphone being configured to detect whether the audio alarm is sounding when activated.

14. The transportable gas detector unit according to claim 1 , wherein the transportable gas detector unit further comprises a pump configured to pump gases from one or more of the one or more source inlets into the chamber.

15. The transportable gas detector unit according to claim 1 , wherein the transportable gas detector unit further comprises a renewable energy generator.

16. The transportable gas detector unit according to claim 1 , wherein the transportable gas detector unit further comprises a plurality of gas sensors, each sensor being positioned within a separate chamber.

17. The transportable gas detector unit according to claim 1 , wherein the transportable gas detector unit further comprises a plurality of gas sensors, each sensor being positioned within a common chamber.