In order to allow an analyzer to be calibrated or a sampling channel to be purged without removing a sampling probe from a sampling location, provided are a sampling channel through which an exhaust gas from an internal combustion engine flows, an analyzer that is connected to the sampling channel and analyzes the exhaust gas, a diluter provided upstream of the analyzer in the sampling channel, a recirculated channel that branches from a branch point set between the analyzer and the diluter in the sampling channel and joins the diluter, a pump that is provided in the recirculated channel and guides part of the exhaust gas from the branch point to the diluter, an additional channel that is connected to the recirculated channel or the sampling channel and through which a calibration gas or a purge gas flows, and an opening and closing mechanism provided in the additional channel.

There is disclosed a method of calibrating a gas sensor comprising a luminescent compound having a luminescence lifetime that is quenched by a gaseous substance which uses a model of the relationship between the luminescence lifetime and the concentration of the gaseous substance that is modified by a calibration factor representing a proportion of the compound not being exposed to the gaseous substance, the method comprising: measuring values of the luminescence lifetime of the luminescent compound while the gas sensor is exposed to at least two known concentrations of the gaseous substance; and deriving the calibration factor from the measured values of the luminescence lifetime using the model. Also disclosed are a corresponding gas sensor apparatus for measuring the concentration of a gaseous substance in an environment, and method of measuring a concentration of a gaseous substance in an environment using a gas sensor.

This invention is a gas standard preparation device and method of use for creating a reference material or a certified reference material. The reference material or the certified reference material is used to quantitate air from a collected sample. This is beneficial for identifying if the air within the area contains certain volatile compounds or other undesired compounds. This is accomplished by providing a sealed ampule containing reference material that is eventually broken by the gas preparation device. Once the ampule is broken, the reference material within the ampule is mixed with a diluent gas and forced into a reference material cylinder. The concentration of the final reference material within the reference material cylinder is verified for use in testing collected air sample. Accordingly, this device allows for creating a custom reference material onsite in a laboratory without the need for shipping in pre-made compressed gas cylinders for air quality testing.

A molecular detection apparatus according to a embodiment includes: a collection unit which collects detection target gases each containing molecule to be detected; a concentration adjusting unit which dilutes and/or concentrates the molecule, and generates a plurality of detection target gases having different concentrations of the molecule; a detection unit to which the plurality of detection target gases are sequentially introduced, and which includes a plurality of detection cells each outputting detection signals based on the concentrations of the molecule in the plurality of detection target gases; and a discrimination unit which discriminates the molecule by change tendencies of the detection signals based on the concentrations of the molecule.

An odor evaluation device, including: a gas chromatograph including a separation column configured to temporally separate a plurality of components contained in an odoriferous analysis-target gas; a timing detector configured to detect, for each of the plurality of components, a timing at which the component exits from the separation column; a gas collector configured to collect, into a sample bag, a gas containing all or some of the components exiting from the separation column when the analysis-target gas is passed through the separation column; a timing setter configured to allow a setting of a timing at which a component contained in the gas to be collected into the sample bag exits from the separation column; and a gas introducer configured to introduce a dilution gas into a passage connecting the separation column and the sample bag.

A system that includes a gas sensor, a fresh air flow controller, a sample flow controller, and a system controller. The fresh air flow controller is configured to deliver fresh air to the gas sensor. The sample flow controller is configured to deliver a sample to the gas sensor. The system controller has a processor connected to memory storing instructions that are executable by the processor. When executed, the instructions cause the processor to determine an intermix ratio of the sample to the fresh air, instruct the fresh air flow controller and the sample flow controller to deliver the fresh air and the sample, respectively, to the gas sensor in accordance with the intermix ratio, and receive a sensor reading from the gas sensor after the fresh air flow controller and the sample flow controller have adjusted the fresh air and the sample, respectively.

A gas mixing device for a NOx detector includes a 3/2 way gas valve having a diaphragm, a first inlet port, a second inlet port, and an exit port. A gas conduit connects the exit port to a gas mixing chamber. A controller controls the diaphragm to alternate between a first position and a second position. The first inlet port may receive a sample gas and the second inlet port may receive ozone gas. In the first position of the diaphragm, a bolus of sample gas enters the conduit, and in the second position of the diaphragm, a bolus of ozone enters the conduit. The alternating boluses of sample gas and ozone mix within the conduit and within the mixing chamber. A NOx detection instrument includes the gas mixing device, an ozone gas source, and an NO.sub.2 sensor in fluid communication with the mixing chamber.

An emissions test system includes an emissions analyzer, a contamination index module, and a diagnostic module. The emissions analyzer is configured to determine a concentration of an emission in a sample of exhaust gas from an engine. The contamination index module is configured to determine a contamination index based on at least two of a flow rate of the exhaust gas sample, the concentration of the emission in the exhaust gas sample, an operating duration of the emissions test system, a pressure of the exhaust gas, and a temperature of the exhaust gas. The diagnostic module is configured to identify potential contamination of at least one of the emissions test system and a component in the emissions test system based on the contamination index.

A refrigerant identification assembly includes a housing that has a high pressure inlet, a low pressure inlet and a purge outlet. A high pressure hose is fluidly coupled to the high pressure inlet for fluidly coupling to a high pressure refrigerant line of an HVAC system. A low pressure hose is fluidly coupled to the low pressure inlet for fluidly coupling to a low pressure refrigerant line of an HVAC system. A refrigerant sensor is positioned within the housing and the refrigerant sensor is in fluid communication with each of the high pressure inlet and the low pressure inlet. In this way the refrigerant sensor can sense the type of refrigerant used in the air conditioning system. A refrigerant display is coupled to the housing and the refrigerant display is in communication with the refrigerant sensor to communicate the type of refrigerant to the user.

A Discrete Sample Introduction Module (DSIM) apparatus includes an internal tubing system to receive into the DSIM apparatus a discrete gas sample having a received concentration. A plurality of valves selectively partitions the internal tubing system to form a plurality of loops corresponding to a plurality of loop volumes to contain the discrete gas sample. The plurality of loop volumes receives a carrier gas to dilute the discrete gas sample to a plurality of preselected dilutions. The DSIM apparatus circulates a given one of the plurality of preselected dilutions for analysis by a spectrometer coupled to the DSIM apparatus.