Methods, systems, and computer-readable medium to perform operations comprising identifying a first gas level of a gas at a first location at a first time; determining that the first gas level of the gas is above a first threshold; in response to determining that the first gas level of the gas is above the first threshold, identifying a second gas level of the gas at a second location at a second time; determining that the second gas level of the gas is above a second threshold; in response to determining that the second gas level of the gas is above the second threshold, calculating a difference between the second time and the first time; based on the difference, determining that one of the first location and the second location as a source of the gas; and providing an alert based on determining the location of the source of the gas.

A gas sensor includes a sensor element, an elastic insulating member, a plurality of lead wires, a plurality of metal terminals, and a ceramic housing. The plurality of lead wires are inserted in the elastic insulating member. The plurality of metal terminals each have a first end electrically connected to the sensor element, and a second end electrically connected to a corresponding one of the plurality of lead wires. The ceramic housing includes a plurality of insertion portions each including a through hole in which a corresponding one of the plurality of metal terminals is inserted, and at least one of the plurality of insertion portions has a different height from other insertion portions.

An apparatus for measuring a concentration of a target gas includes: a gas sensor including a sensing layer having an electric resistance that changes by an oxidation reaction or a reduction reaction between gas molecules and the sensing layer; and a processor configured to, in response to the target gas being introduced along with air into the gas sensor, monitor a change of the electric resistance of the sensing layer and determine the concentration of the target gas by analyzing a shape of the change of the electric resistance.

A quality control method for the preparation of dry compressed gas cylinder including passivating and/or preparing the compressed gas cylinder with the technique to be validated, filling the passivated/prepared compressed gas cylinder with gaseous carbon dioxide to a normal working pressure, wherein the gaseous carbon dioxide has a known .sup.18O isotope ratio, maintaining the pressurized gas cylinder at ambient temperature for a first predetermined period of time, and gradually emptying the pressurized gas cylinder, while simultaneously measuring the .sup.18O isotopic ratio, wherein a predetermined variation in the measured isotopic ratio of .sup.18O indicates a properly prepared cylinder.

A gas-measuring system (100) measures and outputs a gas concentration and includes a gas sensor (110), a digitization module (120), a network (130), an analysis unit (140) and an output unit (150). The gas sensor outputs a raw data signal (112). The digitization module processes the raw data signal and outputs a corresponding digital sensor signal (124) via a wireless module (126) to the network. The digital sensor signal includes the processed raw data signal and sensor identification information. The analysis unit reads the digital sensor signal from the network, to determine the gas concentration of the gas to be tested based on the measured raw data indicated by the digital sensor signal, and outputs a corresponding digital concentration signal (142) to the network. The output unit reads the digital concentration signal from the network and provides a corresponding output (154) via an output module (152).

Devices for micro-fluid mixing micro-fluids are presented, together with example methods for micro-mixing using example devices. An example device may include a micro-volume fluid chamber (VFC), a micro-volume mixing chamber (VMC), and a source of a target micro fluid. The VFC may include two slidably-mounted piston segments that divide the VFC into three sub-volumes, one of which initially contains a mixer micro-fluid. The source of the target micro fluid may be triggered to deliver the target micro-fluid into another of the sub-volumes via an inlet channel. A propellant may be triggered to drive axial motion of the piston segments, causing the sub-volumes to compress. Through this action, the mixer micro-fluid may be expelled via a first outlet channel into the VMC, and the target micro-fluid may be expelled via a second outlet channel into the VMC. As the piston segments move, they block and unblock the inlet and outlet channels.

A system and method provides a more precise mole delivery amount of a process gas, for each pulse of a pulse gas delivery, by measuring a concentration of the process gas and controlling the amount of gas mixture delivered in a pulse of gas flow based on the received concentration of the process gas. The control of mole delivery amount for each pulse can be achieved by adjusting flow setpoint, pulse duration, or both.

A concentration measurement method for measuring a concentration of impurities includes a step of irradiating a DUT 10 serving as a measurement target object with measurement light and stimulus light subjected to intensity modulation using a modulation signal including a default frequency, a step of outputting a detection signal by detecting an intensity of reflected light from the DUT 10 or transmitted light through the DUT 10, and a step of detecting a phase delay of the detection signal with respect to the modulation signal, obtaining a frequency at which the phase delay has a predetermined value, and estimating a concentration of impurities in the measurement target object on the basis of the frequency.

A steam quality process monitor system and method includes a temperature sensor, a pressure sensor, a processor and memory configured: to determine a steam quality value of an input steam supply based on a reading of the temperature sensor and a reading the pressure sensor; continuously update the steam quality value; and a machine that accepts the input steam supply and is at least partially controlled by the steam quality value. A steam quality process monitor system and method includes a temperature sensor, a pressure sensor, a processor and memory configured: to determine a steam quality value of an input steam supply based on a reading of the temperature sensor and a reading the pressure sensor; continuously update the steam quality value; and a machine that accepts the input steam supply and is at least partially controlled by the steam quality value.

Embodiments relate generally to a gas detector test fixture (102) that recycles test gas, which can then be reused. A portable gas detector test fixture (102), comprises a test chamber (104), a processor (134), a docking connector (132) communicatively coupled to the processor (134), an output device (138) communicatively coupled to the processor (134), a memory (136) communicatively coupled to the processor (134), and an application (137) stored in the memory (136) that, when executed by the processor (134), is configured to conduct a bump test on a portable gas detector (106) plugged into the docking connector (132) and to output the bump test result to the output device (138). The test fixture (102) further comprises an inflow line (124) configured to connect to a test gas supply line (120) of a test gas container (118), where the inflow line (124) is coupled to the test chamber (104), and an outflow line (130) configured to connect to a test gas return line (126) of the test gas container (118), where the outflow line (130) is coupled to the test chamber (104).