A method to simulate distillation of a petroleum stream by gas chromatography can include separating the petroleum stream with a gas chromatograph as a function of boiling point; passing the separated petroleum stream through a vacuum ultraviolet detector to yield data comprising a vacuum ultraviolet signal as a function of boiling point; integrating the vacuum ultraviolet signal as a function of boiling point over two or more wavelength ranges to derive relative concentrations of two or more components of the separated petroleum stream that correspond to the two or more wavelength ranges.

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.

A gas ionization chamber, includes a first electrode, a fence electrode disposed below the first electrode, a second electrode disposed below the fence electrode, a first dielectric layer disposed between the first electrode and the fence electrode, and a second dielectric layer disposed between the fence electrode and the second electrode. The first and second electrodes, and the first and second dielectric layers include a plurality of aligned holes forming channels configured to permit gas flow between the first electrode to the second electrode through an opening in the fence electrode, the plurality of aligned holes being arranged in a pattern having a central region with a first set of aligned holes and a peripheral region having a second set of aligned holes, and wherein a diameter of at least one hole of the first set of aligned holes is less than or equal to about 0.5 millimeters.

The invention relates to a system and micro monitor apparatus, a space-, time-, and cost-efficient device to concentrate, identify, and quantify organic compounds in gas environments. The invention further relates to a method centered on gas chromatography for identifying and quantifying organic compounds in gas environments, using air as the carrier gas, without the need for a compressed pre-bottled purified carrier gas.

A method of detecting gas includes determining and storing, by a controller, a zero level of a photoionization detector using ambient air inflow when an ultraviolet lamp is in a turned OFF state, wherein the stored zero level is based on an ambient temperature; sampling, by the controller, an output of a detector electrode of the photoionization detector when the ultraviolet lamp is in a turned ON state; and comparing the sampled output of the detector electrode to the stored zero level to determine if a threshold concentration of a gas is present.

A method of detecting gas includes determining and storing, by a controller, a zero level of a photoionization detector using ambient air inflow when an ultraviolet lamp is in a turned OFF state, wherein the stored zero level is based on an ambient temperature; sampling, by the controller, an output of a detector electrode of the photoionization detector when the ultraviolet lamp is in a turned ON state; and comparing the sampled output of the detector electrode to the stored zero level to determine if a threshold concentration of a gas is present.

The invention relates to a system and micro monitor apparatus, a space-, time-, and cost-efficient device to concentrate, identify, and quantify organic compounds in gas environments. The invention further relates to a method centered on gas chromatography for identifying and quantifying organic compounds in gas environments, using air as the carrier gas, without the need for a compressed pre-bottled purified carrier gas.

A volatile organic compound (VOC) testing system is provided that includes a plurality of valves, and a plurality of pumps. At least one of the pumps is coupled to at least one of the valves. A plurality of sensors are coupled to the pumps and at least one of the valves. The sensors detect one or more volatile organic compounds.

A microfluidic photoionization detector (PID) may include a substrate and an electrically conductive layer formed on the substrate. The electrically conductive layer may include a microchannel, and a first electrode region and a second electrode region separated from each other by the microchannel, an ohmic contact layer formed on top of the first electrode region and the second electrode region, and a light source formed on the ohmic contact layer for emitting light toward the microchannel.

A method of detecting gas includes determining and storing, by a controller, a zero level of a photoionization detector using ambient air inflow when an ultraviolet lamp is in a turned OFF state, wherein the stored zero level is based on an ambient temperature; sampling, by the controller, an output of a detector electrode of the photoionization detector when the ultraviolet lamp is in a turned ON state; and comparing the sampled output of the detector electrode to the stored zero level to determine if a threshold concentration of a gas is present.