Low power photoionization detector (PID)
AssigneeHoneywell International Inc.
InventorsPeter Hsi, Wei Yeh, Dan Zhang, Yuhui Xu, Kui Lu
Life of this patent
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Abstract
A photoionization detector is disclosed. The photoionization detector comprises a detector electrode that outputs a signal, an ultraviolet lamp, a lamp driver communicatively coupled to the ultraviolet lamp and configured to turn the ultraviolet lamp on and off in response to a control input, and a controller that is communicatively coupled to the output signal of the detector electrode and to the control input of the lamp driver, that outputs an indication of gas detection based on the output signal of the detector electrode, and that turns the lamp driver on and off with an on duty cycle of less than 10%.
Claims18
A photoionization detector, comprising:
- a detector electrode that outputs a signal;
- an ultraviolet lamp positioned in proximity of the detector electrode and configured to radiate ultraviolet light towards the detector electrode;
- a lamp driver communicatively coupled to the ultraviolet lamp, wherein the lamp driver is configured to turn the ultraviolet lamp on and off in response to a control input;
- a filter that receives the signal output from the detector electrode and outputs a filtered detector electrode signal;
- an analog-to-digital converter that receives the filtered detector electrode signal from the filter and outputs a digital filtered detector electrode signal;
- and
- a controller communicatively coupled to the analog-to-digital converter and communicatively coupled to the control input of the lamp driver,
- wherein the controller is configured to:
- receive the digital filtered detector electrode signal,
- output an indication of gas detection based on the received digital filtered detector electrode signal,
- turn the analog-to-digital converter on and off to achieve an on duty cycle of less than 1%,
- turn the analog-to-digital converter on when the lamp driver is turned off and turn the analog-to digital converter off before the lamp driver is next turned on, and
- turn the lamp driver on and off with an on duty cycle of less than 10%.
A method of detecting presence of gas with a photoionization detector (PID), comprising:
- turning an ultraviolet lamp on and off periodically by a controller, where the on duty cycle is less than 10%,
- while the ultraviolet lamp is turned off, sampling an output of a detector electrode;
- analyzing, by the controller, the sampling of the output of the detector electrode;
- and
- outputting a gas detection indication by the controller based on the analysis of the sampling of the output of the detector electrode.
A photoionization detector, comprising:
- a detector electrode that outputs a signal;
- an ultraviolet lamp positioned in proximity of the detector electrode and configured to radiate ultraviolet light towards the detector electrode;
- a lamp driver communicatively coupled to the ultraviolet lamp, wherein the lamp driver is configured to turn the ultraviolet lamp on and off in response to a control input;
- a filter that receives the signal output by the detector electrode and outputs a filtered detector electrode signal;
- an analog-to-digital converter coupled to the filter and to a controller, wherein the analog-to-digital converter converts the filtered detector electrode signal to a digital filtered detector electrode signal, and wherein the controller is configured to:
- receive the digital filtered detector electrode signal;
- outputs an indication of gas detection based on the filtered detector electrode signal output by the filter, and that turns the lamp driver on and off, and
- turn the analog-to digital converter on when the lamp driver is turned off and turns the analog-to-digital converter off before the lamp driver is next turned on.
Dependencies are inferred from the claim text.