56 results about "Photoionization detector" patented technology

The utility model relates to the technical field of organic matter detection, in particular to an online photoionization detector system for measuring volatile organic compounds, which comprises a gas circuit module, an ionization module, a signal amplification module, a data storage module and a power supply module. The gas path module is used for collecting and guiding gas and realizing real-time monitoring of gas flow, gas path temperature and humidity; the ionization module can efficiently ionize to-be-detected gas, an ionization chamber in the ionization module can efficiently capture gas ions and electrons, interference of environmental condition changes on signals is reduced, and generated current signals and the concentration of the to-be-detected gas are in a linear relation; the signal amplification module amplifies the generated current and converts the current into a voltage signal, and the amplification efficiency can reach 109 times; the data storage module records and stores the voltage signal to realize online data visualization; the power supply module provides working voltage for the detector system. The system is high in integration degree, strong in stability and high in sensitivity, and the detection limit is superior to 0.5 ppbv.

An electrode stack assembly includes an electrically insulative substrate having a cavity therethrough extending, a first counter electrode on a top surface thereof and extending through the substrate, a second sensing electrode on a bottom surface thereof and extending through the substrate, and a third electrode having a top body portion on a top of the substrate, a bottom body portion on a bottom of the substrate, and a coupling pin passing through the substrate and electrically coupling the top and bottom body portions. The third electrode electrically separates the pin of the sensing electrode from the counter electrode.

The ionization chamber comprises a negative electrode and a positive electrode, the negative electrode and the positive electrode are arranged in an overlapped mode, an ultraviolet lamp is arranged on one side of the positive electrode or the negative electrode, the negative electrode and the positive electrode are each provided with an air flow channel communicated with each other, the ultraviolet lamp is located at the inner end of the air flow channel, and the ultraviolet lamp is located at the outer end of the air flow channel. A high-voltage structure is arranged on the edge of an airflow channel of the negative electrode or the positive electrode. The high-voltage structure is arranged on the edge of the gas flow channel of the negative electrode or the positive electrode, so that the high collection efficiency of VOCs gas molecule ionization products is ensured. According to the photoionization detector provided by the utility model, a high bias voltage does not need to be additionally applied to eliminate the noise influence, and a complex hardware circuit or a humidity compensation algorithm does not need to be additionally arranged, so that the manufacturing cost and the failure rate of the photoionization detector are favorably controlled, and the development, debugging and maintenance costs of enterprises are also favorably reduced.

A method for enhanced mud gas logging includes receiving a gas stream; separating the gas stream into a first gas stream, a second gas stream, and a third gas stream; directing the first gas stream to a gas chromatography configuration including a gas chromatography column and a photoionization detector; detecting, by the photoionization detector, gas species in the first gas stream; separating, by a first separation component, water vapor from the second gas stream to produce a processed second gas stream; detecting, by a first mass spectrometer, gas species in the processed second gas stream; separating, by a second separation component, water vapor and other gas species from the third gas stream to produce a processed third gas stream; and detecting, by a second mass spectrometer, gas species in the processed third gas stream.

A photoionization detector (PID) is disclosed that includes an ionization chamber configured to allow a flow of a gas sample therethrough, the ionization chamber defining an ionization region and a detection region, a photoionization source configured to generate ionizing radiation for irradiating the flow of the gas sample in the ionization region, an electric-field ionization source configured to apply an ionizing electric field inside the ionization chamber to intersect the flow of the gas sample in the ionization region, the ionizing radiation and the ionizing electric field being configured to ionize the gas sample, and an ion detector configured to detect, in the detection region, an ionization current resulting from the ionized gas sample. The PID may also include an optical window, for example, made of a window material including sapphire, configured to allow at least part of the ionizing radiation to pass therethrough prior to entering the ionization region.

A photo-ionization detector (PID) comprising: a UV source; an ionization chamber for receiving sample gas; a plurality of electrodes, forming an electrode stack module, for detecting gaseous analyte ionized in the ionization chamber; a controller; and at least one sensor in electronic communication with the controller for measuring a condition of the sample gas. The electrode stack module comprises a memory.

The application discloses an ionization chamber of a photo-ionization detector, comprising a negative electrode and a positive electrode, the negative electrode and the positive electrode are arranged in an overlapping mode, an ultraviolet lamp is arranged on one side of the positive electrode or the negative electrode, the negative electrode and the positive electrode are both provided with airflow channels which are in communication with each other, the ultraviolet lamp is located at the inner end of the airflow channels, and the airflow channel edge of the negative electrode or the positive electrode is provided with a high-voltage structure. The high-voltage structure arranged at the airflow channel edge of the negative electrode or the positive electrode can ensure the high collection efficiency of the ionization product of VOCs gas molecules. Therefore, it is unnecessary to additionally apply a higher bias voltage to eliminate the noise influence, and it is also unnecessary to additionally set a complex hardware circuit or a humidity compensation algorithm, so that the manufacturing cost and the failure rate of the photo-ionization detector can be controlled, and the development, debugging and maintenance costs of enterprises can be reduced.

The present invention provides a planar photoionization detector and a planar photoionization detector sensor, the planar photoionization detector comprising: a gas discharge lamp that ionizes a molecule of interest to produce ionized molecules and electrons; and a sensor having at least one opening for passage of UV light, and a conductive pattern on at least one of a top surface and a bottom surface of the plate, the conductive pattern including at least a negative potential pattern and a collector pattern. The ionized molecules may be collected by a bias electrode and electrons may be collected by a collector. The negative potential pattern includes a linear portion and a polarizing plate. The collector pattern includes a conductive line suspended across the at least one opening and a linear portion located on a surface opposite the conductive line. The conductive pattern may further include a ground potential conductive pattern having a first portion on the top surface and a second portion on the bottom surface.

Methods, apparatus, and systems are provided for providing an alternating current (AC) voltage supply to a photoionization detector lamp from a direct current (DC) voltage source. Example apparatus may include a DC voltage to DC voltage (DC / DC) converter circuit; and a feedback circuit that is electronically coupled to the DC / DC converter circuit and converts a reference AC voltage into a feedback DC voltage for the DC / DC converter circuit. In some examples, the feedback circuit may be electronically coupled to a DC voltage to AC voltage (DC / AC) conversion circuit to obtain the reference AC voltage.

Embodiments are provided for ultraviolet lamps for use in photoionization detectors and methods of manufacturing same. An example method of manufacturing an ultraviolet lamp includes providing a glass tube, the glass tube defining a first end; applying a mixed powder coating composition onto an edge surface of the first end of the glass tube, the mixed powder coating composition comprising indium powder and glass powder; applying a glass powder coating composition over the mixed powder coating composition; attaching a crystal window to the edge surface of the first end of the glass tube; and heating the glass tube and the crystal window to seal the crystal window to the glass tube.

The invention relates to a photo ionization (PID) detector with a firing failure alarm system. The PID detector comprises an ultraviolet (UV) lamp, a sensing electrode, an ignition electrode, a driver, an ignition failure alarm circuit and a processor. The firing failure alarm circuit is operable to detect the absence of ultraviolet radiation emitted by the ultraviolet lamp after the driver attempts to ignite the ultraviolet lamp, and to alert the ultraviolet lamp when the driver attempts to ignite the ultraviolet lamp and detects the absence of ultraviolet radiation emitted by the ultraviolet lamp after the driver attempts to ignite the ultraviolet lamp. An abnormally violent, human-perceivable, high-low oscillation of the reported target analyte concentration is generated.

A method, apparatus, and computer program product for detecting volatile organic compounds (VOCs) in a gas is provided. An example VOC detector may include a processing device and a detecting region. The detecting region may further include a first interdigital pole electrically connected to a separation voltage source, a second interdigital pole electrically connected to a switch, and an ionization device configured to interact with the gas within the detecting region to create a plurality of ionized gas molecules. To facilitate detection of VOCs, the switch may alternate the connection of the second interdigital pole between a compensation voltage source and the processing device. The processing device may determine a number of volatile organic compounds in the gas based at least in part on a number of ionized gas molecules that contact the second interdigital pole while the second interdigital pole is electrically connected to the processing device.

The invention discloses a high-flux vacuum ultraviolet light source device, which belongs to the technical field of high-end analytical instrument components, and comprises a radio frequency power amplification excitation mechanism, a heat dissipation mechanism, a discharge medium gas circuit mechanism, a vacuum sealing mechanism and a light emitting mechanism, one end of the light-emitting mechanism is connected with the discharge medium gas circuit mechanism, the other end of the light-emitting mechanism is connected with the vacuum sealing mechanism, and a gas inlet pipe and a gas outlet pipe of the discharge medium gas circuit mechanism penetrate through the heat dissipation mechanism. The high-flux vacuum ultraviolet light source device has the advantages of being small in size, high in luminous flux, stable in output, long in service life and the like, and can be widely applied to the fields of mass spectrometry, spectral analysis, photoelectron spectroscopy analysis, chromatographic photoionization detectors, basic physical research and the like; and the requirement of a high-end analysis instrument on a high-performance vacuum ultraviolet light source is met.

The invention provides an ultraviolet lamp used in a photoionization detector, the ultraviolet lamp comprises a lamp tube, a metal sheet, a sealing layer and an ultraviolet light window sheet, the lamp tube is filled with inert working gas, the metal sheet is arranged on the inner wall of the lamp tube, the sealing layer is arranged on the inner wall of the lamp tube, and the ultraviolet light window sheet is arranged on the inner wall of the lamp tube. The sealing layer is connected between the lamp tube and the ultraviolet light window sheet so as to keep the air tightness of the interior of the lamp tube, and the ultraviolet light window sheet enables ultraviolet light generated by excitation of the inert working gas to penetrate through and output to the outside. According to the ultraviolet lamp, due to the arrangement of the metal sheets in the lamp tube, inert gas molecules in the ultraviolet lamp can be excited more quickly, so that the working state entering speed of the ultraviolet lamp is remarkably increased.

This utility model discloses a zeolite rotor device for efficiently treating organic waste gas from coating processes. The device includes a rotor box containing a zeolite rotor. An inlet pipe is fixedly installed at the front end of one side of the rotor box, and an outlet pipe is fixedly installed at the front end of the other side. A detection box is fixedly installed on one side of the outlet pipe, and a photoionization detector is fixedly installed above the detection box. An electric valve is fixedly installed at the front end of the detection box, and a connecting pipe is fixedly installed at the front end of the electric valve. An output pipe is fixedly installed at one end of the connecting pipe. An electric valve is fixedly installed at the rear end of the detection box, and a reflux pipe is fixedly installed at the rear end of the electric valve. This device achieves reflux treatment capability, increasing its practicality and solving the problem that a single pass through the zeolite rotor cannot stably remove organic matter from waste gas containing various types of organic matter or with high concentrations of organic matter.

A photoionization detector (PID) and method for PID is disclosed. The PID comprises a primary pole and a secondary pole spaced apart from the primary pole. The secondary pole is coupled to a bias voltage source. The secondary pole is exposed to ultraviolet (UV) light emitted from at least one UV light source for generating photo-induced electrons. The PID further comprises at least one gas port associated with the secondary pole configured to flow gas in between the primary pole and the secondary pole for absorbing the UV light to alter the generated photo-induced electrons.

The invention discloses a rapid detection method for volatile organic compounds, and relates to the field of environmental detection.The method comprises the steps that the carrier gas flow of a gas inlet pipeline is adjusted from the initial flow to the measured flow, and the flow speed of volatile organic compound sample gas is adjusted; the method comprises the following steps: adsorbing volatile organic compound sample gas in a pre-concentration pipe based on flow rate control of the volatile organic compound sample gas; when the temperature of the pre-concentration tube reaches a target temperature, the volatile organic compound sample gas is separated from the pre-concentration tube and enters the chromatographic column along with the carrier gas; controlling the temperature of the chromatographic column by utilizing a constant-temperature control mode and a proportional heating mode; through temperature control of the chromatographic column, different substances in the volatile organic compound sample gas are gradually separated from the chromatographic column and enter a photoionization detector; and detecting the components of different substances in the volatile organic compound sample gas by using a photoionization detector. The photoionization detector and the gas chromatography are combined, so that the detection efficiency of the volatile organic compounds is improved.

The invention discloses a biomass derived porous material adsorbability testing method and a detection device, the detection device comprises a gas phase pipeline system, a liquid phase pipeline system and a flushing pipeline system, the gas phase pipeline system comprises a multi-way valve I, a gas storage tank, a gas circulating pump and a gas heater which are connected in sequence; the liquid phase pipeline system comprises a multi-way valve I, a liquid storage tank, an anti-corrosion circulating pump and a liquid heater which are connected in sequence, the flushing pipeline system comprises a multi-way valve I and a standard state flushing pipeline, and the reactor system comprises a multi-way valve II, a reactor, a detection instrument, an outlet valve and a photoionization detector which are connected in sequence. According to the invention, by integrating the multi-parameter working condition simulation module, the in-situ regeneration test module and the multi-channel parallel test module, the integrated test of static / dynamic adsorption, multi-parameter coupling, in-situ regeneration and cyclic verification is realized, the defects of simplification, fragmentation and poor scene adaptability of the existing equipment are overcome, and the detection accuracy and the detection efficiency are improved.

A method for enhanced mud gas logging includes receiving a gas stream; separating the gas stream into a first gas stream, a second gas stream, and a third gas stream; directing the first gas stream to a gas chromatography configuration including a gas chromatography column and a photoionization detector; detecting, by the photoionization detector, gas species in the first gas stream; separating, by a first separation component, water vapor from the second gas stream to produce a processed second gas stream; detecting, by a first mass spectrometer, gas species in the processed second gas stream; separating, by a second separation component, water vapor and other gas species from the third gas stream to produce a processed third gas stream; and detecting, by a second mass spectrometer, gas species in the processed third gas stream.

A method of detecting gas with a photoionization detector, PID, system (1, 100), comprising: determining and storing, by a controller (2, 102), a zero level of a photoionization detector (4, 104, 106, 108, 112, 116), using ambient air flowed from surrounding environment past a detector electrode (108) of the photoionization detector (4, 104, 106, 108, 112, 116), wherein the stored zero level is based on an ambient temperature; sensing the ambient temperature; adapting the stored zero level algorithmically based on a change sensed in the ambient temperature; sampling, by the controller (2, 102), an output of the detector electrode (108) of the photoionization detector (4, 104, 106, 108, 112, 116) when an ultraviolet lamp (106) is in a turned ON state; and comparing the sampled output of the detector electrode (108) to the stored zero level to determine if a threshold concentration of a gas is present.

The invention discloses a driving and high-voltage biasing circuit applied to a photoionization detector, and relates to the field of photoionization detectors, and the circuit comprises a DC-DC chip, a transformer, an NMOS tube, a feedback loop and a rectification filter circuit. A pin 5 of the DC-DC chip is connected with the feedback loop, a pin 6 of the DC-DC chip is respectively connected with an S pole of the NMOS tube and the ground, a pin 8 of the DC-DC chip is connected with a G pole of the NMOS tube, a pin 9 of the DC-DC chip and a pin 1 of the transformer are both connected with the power supply, and a pin 10 of the DC-DC chip is connected with the single-chip microcomputer; the D pole of the NMOS tube is respectively connected with the pin 3 and the pin 4 of the transformer; a pin 6 of the transformer is connected with the rectification filter circuit. The feedback loop is also connected with the rectification filter circuit. The high-voltage bias electric field can be applied to the electrodes while the UV lamp can be efficiently driven, and the light intensity of the UV lamp is adjustable.

The present invention relates to a photoionization detector, which includes a sensor having at least a collector electrode and a ground electrode, a gas discharge lamp that ionizes molecules of interest to produce ionized molecules and electrons, and an amplifier connected to the collector electrode. Each of the collector electrode and the ground electrode includes a feedthrough pin; an inner trace surrounding the feedthrough pin; an outer trace surrounding the inner trace, wherein the outer trace on each electrode includes the same material; a channel between the inner trace and the outer trace, wherein the channel includes a material different from the outer trace and the inner trace; and a bridge connecting the outer trace to the inner trace. The ionized molecules can be collected by a bias electrode, and the electrons can be collected by the collector electrode.

This invention discloses a self-cleaning variable optical path photoionization detector. By setting up a reinforcement structure, an optical path adjustment mechanism, and a self-cleaning mechanism, it achieves variable optical path based on ultraviolet lamp radiation. This greatly facilitates the applicability of the detector, thereby reducing the types of materials, procurement cycle, and detector cost. The variable optical path of the detector means a wider concentration detection range. One detector can be used in multiple scenarios without affecting the overall equipment size. The whole equipment does not need to be redesigned or compatible with different specifications of detectors. At the same time, the self-cleaning mechanism realizes the self-cleaning function, effectively reducing the equipment maintenance labor cost.

This invention discloses an intelligent refrigeration control system and refrigeration device for Chinese dishes, belonging to the technical field of refrigeration systems. Specifically, it includes: acquiring the temperature sequence of the heated surface and the medium during the cooking stage of the dish; extracting dissipation characteristic parameters and temperature rise parameters and mapping them to fluctuation amplitude, heating duration, and fluctuation period to construct an initial fluctuation condition and obtain a historical attenuation duration reference range; during the refrigeration process, collecting the gas response value sequence through a photoionization detector and determining the dissipation inflection point to obtain the measured attenuation duration; comparing the measured attenuation duration with the reference range and adjusting the fluctuation condition parameters in reverse according to the deviation to control the operation of the refrigeration system. This invention realizes the parameter transfer and closed-loop feedback adjustment from cooking thermal characteristics to refrigeration temperature fluctuation control.

A self-testing photoionisation detector (PID) 200 for determining the concentration of a gaseous compound, comprises; a gas ionisation chamber 206 for receiving the gaseous compound; an ultraviolet lamp 203 configured to ionise the gaseous compound within the gas ionisation chamber; an output sensor 204 configured to produce an output electrical signal that correlates to an ionic current within the gas ionisation chamber; and a control unit 209 configured to generate a control electrical signal 201 for driving the ultraviolet lamp, to increase or decrease the control electrical signal and provide a user alert electrical signal is provided in the absence of a correlation between the control electrical signal or any change in the control electrical signal and the output electrical signal or any change in the output electrical signal, respectively.

Methods and systems for detecting and limiting water in a photoionization detector are provided. The method can include de-energizing a lamp configured to ionize particles of air. The method can also include monitoring a signal from the photoionization detector. The signal can be monitored based on a current between a signal electrode and a bias electrode. In an instance in which the signal is above a signal threshold, the method can also include electrolyzing one or more particles of water present in the photoionization detector by closing a leak switch to allow current to flow through the bias electrode and the signal electrode. In an instance in which the signal is below the signal threshold, the method can include energizing the lamp to begin photoionization detection. Corresponding systems are also provided.

A photoionization detector (PID) lamp assembly and method are disclosed. The PID lamp assembly comprises a cap defining a lamp chamber within and the cap having a step aperture. Further, a crystal window is sealed over the cap and is configured to allow the passing of ultraviolet (UV) light. Further, a capillary tube is sealed to the cap via the step aperture of the cap. Thereafter, a pair of annular grooves are formed on the cap to install a pair of driving pads on the cap.

An integrated microfluidic photoionization detector (PID) is provided, the integrated microfluidic photoionization detector comprising: a microfluidic ionization chamber, a microfluidic ultraviolet radiation chamber configured to generate ultraviolet photons. An ultra-thin transmission window is disposed between the microfluidic ionization chamber and the microfluidic ultraviolet radiation chamber and permits the ultraviolet photons to enter the microfluidic ionization chamber from the microfluidic ultraviolet radiation chamber. A detection system for one or more VOC analytes is also provided, the detection system comprising: a gas chromatography (GC) unit, the gas chromatography unit including at least one gas chromatography column; and an integrated microfluidic photoionization detector (PID) disposed downstream of the gas chromatography (GC) unit.

A photo ionization detector (PID) is disclosed. The PID includes a primary pole and a secondary pole spaced apart from the primary pole. The secondary pole is coupled to a bias voltage source. The secondary pole is exposed to ultraviolet (UV) light emitted from at least one UV light source for generating photoinduced electrons. The PID further includes at least one gas port associated with the secondary electrode, the at least one gas port configured to flow a gas between the primary electrode and the secondary electrode for absorbing UV light to alter the generated photoinduced electrons.