A combined exhaled air and environmental gas sensor apparatus for mobile respiratory equipment includes a housing, wherein the housing includes a port aperture, a connector configured to attach the port aperture to a respiratory exhaust port, and at least an ambient aperture connecting to an exterior environment, a sensor positioned within the housing, the sensor configured to detect a carbon dioxide level and generate sensor outputs indicating detected carbon dioxide level, a processor communicatively connected to the sensor, the processor including a memory, a breath analysis mode and an environmental analysis mode, wherein the processor is configured to receive a plurality of sensor outputs from the sensor, match the plurality of sensor outputs to mode parameter profile, and switch between the breath analysis mode and the environmental analysis mode as a function of the mode parameter profile.

A method for desulfurizing molten steel comprising taking a sample out from molten steel after tapping from a converter or during secondary refining and analyzing the sample rapidly with high accuracy by a method comprising a high frequency induction heating step wherein the sample is combusted and oxidized under the high frequency induction heating in an oxygen atmosphere having an oxygen purity of 99.5 vol % or more to convert S in the sample into SO.sub.2 and an analyzing step wherein SO.sub.2-containing gas produced in the high frequency induction heating step is analyzed through an ultraviolet fluorescence method to quantify S concentration of the sample.

A sulfur oxide detection system includes an element part which includes a sensor cell and a diffusion regulating layer. The sensor cell includes a solid electrolyte layer, a first electrode arranged, and a second electrode. The sulfur oxide detection system also includes a voltage application circuit configured to apply a voltage to the sensor cell so that a potential of the second electrode becomes higher than a potential of the first electrode, and a current detection circuit configured to detect a current flowing between the first electrode and the second electrode. The sulfur oxide detection system further includes a controller coupled with the voltage application circuit and the current detection circuit, and configured to estimate a sulfur oxide concentration in a gas to which the first electrode is exposed by way of the diffusion layer.

Disclosed is a method for predicting corrosion and spontaneous combustion of sulfur-related petrochemical equipment. The method solves the issues in the existing techniques that includes narrow predicting range, high workload in installation and maintenance, and time lag in predicting corrosion and spontaneous combustion inside equipment. The method comprises a step of a dual index system prediction, which includes a step of monitoring a temperature and a step of detecting SO.sub.2 gas generated by spontaneous combustion. The time when spontaneous combustion occurs can be accurately calculated by using a fitted quantitative relationship formula generated by the spontaneous combustion of corrosion products. The method has a low Labor cost. The method has a low labor cost and, does not require on-site gas detection to be carried out by means of manual detection, which both reduces the cost and ensures the detection accuracy.

A gas analyzer via which exhaust gas to be analyzed is conducted untreated through a first measurement chamber and, after treatment in an oxidation device, through a second measurement chamber, wherein ozone is produced from oxygen to thereby convert nitrogen monoxide into nitrogen dioxide, where the gas analyzer has a first light emitting diode and a second light emitting diode, light of both diodes is conducted through the first measurement chamber onto a first detector, light of the first light emitting diode is partly conducted through the second measurement chamber onto a second detector via a beam splitter arrangement, based on the first detector signal, the nitrogen dioxide concentration of the untreated gas is also measured, based on the second detector signal, the nitrogen dioxide concentration of the treated exhaust gas is measured, and the nitrogen oxide concentration of the exhaust gas is additionally determined from measured nitrogen dioxide concentrations.

Systems, devices, and methods for a gas sensor comprising one or more optical cells; a processor having addressable memory, the processor configured to: detect gas from the one or more optical cells of the gas sensor, where the detected gas is one or more of: methane, carbon dioxide, hydrogen sulfide, water, ammonia, sulfur oxides, and nitrogen; record data corresponding to the detected gas, where the recorded data comprises at least one of: an ambient temperature from a temperature sensor, an ambient pressure from a pressure sensor, an aerial vehicle telemetry, and an aerial vehicle location from a global positioning system (GPS); and generate a map of atmospheric greenhouse gas concentration on a map based on the detected gas and the recorded data.

A measurement apparatus includes: a number concentration measurement device configured to measure a number concentration of particles in a air; a humidity measurement device configured to measure a humidity of the air; and a air concentration measurement device configured to measure a concentration of a specific air in the air, wherein a mass concentration of the particles in the air is calculated based on a measured number concentration, a measured humidity, a measured concentration of the specific air, and a predetermined correlation between the number concentration, the humidity, and the concentration of the specific air, and the mass concentration of the particles in the air.

The invention of the present application relates to a system for accurately measuring fine-dust precursors. Among apparatuses that measure concentrations of NO.sub.x and SO.sub.x which are precursors of fine dust by use of tunable diode laser absorption spectroscopy (TDLAS), an apparatus that can control a temperature of a measurement cell equipped with prism-type multi-passes by using thermoelectric elements without vibration is provided.

According to one embodiment, a chemical sensor includes a sensor element. The sensor element includes a sensitive film and a treatment material. Physical properties of the sensitive film vary as bonding of a target substance to the sensitive film. The sensor element is configured to detect the variation in the physical properties. The treatment material is configured to carry out a treatment onto the target substance before the target substance bonds to the sensitive film. The treatment enhances the variation in the physical properties as compared to a case without the treatment.

An apparatus, method and sensor for measuring gas concentration. The apparatus includes a sensing unit and a processing unit. The sensing unit includes a first selective water vapour-permeable membrane, a first working electrode and a second working electrode. The first selective water vapour-permeable membrane allows the first working electrode to be in contact with water molecules while to prevent this first working electrode from being in contact with the gas molecules to be measured. The first working electrode generates an electrical signal caused by change in relative humidity, the second working electrode generates a superimposed electrical signal caused by the change in relative humidity and the gas molecules to be measured, and the processing unit acquires concentration of the gas based on the electrical signal and the superimposed electrical signal.