An improved fire detector test device and methods for conducting field sensitivity and functionality testing of a fire detector in-situ are provided. The test device can include ambient condition or stimulus generating devices and a programmable processor, wherein the programmable processor can identify information about a detector under test, wherein the programmable processor can obtain a configuration file based on the identified information about the detector under test, wherein the configuration file can identify a combination, level, or rate of a plurality of stimuli that cause an alarm in the detector under test, and wherein the programmable processor can execute the configuration file to cause the ambient condition or stimulus generating devices to generate and emit the plurality of stimuli in the combination and at the level and the rate identified in the configuration file.

A particulate matter sensor assembly including a resistance sensor and a resonance sensor. Each one of the resistance sensor and the resonance sensor is configured to measure particulate matter present in engine exhaust.

There is provided an optical machine of a smoke detector including a substrate, a light source, a light sensor and a light blocking member. The light source and the light sensor are arranged on the substrate in a first direction. The light blocking member is arranged upon the light source and blocks a part of an emission angle of the light source in the first direction far away from the light sensor.

The state of a flame in a gas turbine engine combustor is acoustically monitored using a dynamic pressure sensor within the combustor. A spectral pattern of a dynamic pressure sensor output signal from the sensor is compared with a characteristic frequency pattern that includes information about an acoustic pattern of the flame and information about acoustic signal canceling due to reflections within the combustor. The spectral pattern may also be compared with a characteristic frequency pattern including information about a flame-out condition in the combustor.

A cap for a gas sensor module is described herein. The cap can include at least one wall forming a cavity having a first portion and a second portion. The cap can also include an inlet tube coupling feature disposed in the at least one wall, where the first location is adjacent to the first portion of the cavity. The cap can further include an outlet tube coupling feature disposed in the at least one wall, where the second location is adjacent to the second portion of the cavity. The cap can also include a distribution channel coupling feature disposed in the at least one wall, where the third location is adjacent to the first portion of the cavity. The cap can further include a receiving channel coupling feature disposed in the at least one wall, where the fourth location is adjacent to the second portion of the cavity.

There is provided an optical machine of a smoke detector including a substrate, a light source, a light sensor and a light blocking member. The light source and the light sensor are arranged on the substrate in a first direction. The light blocking member is arranged upon the light source and blocks a part of an emission angle of the light source in the first direction far away from the light sensor.

The state of a flame in a subject combustor of a gas turbine engine is acoustically monitored using a dynamic pressure sensor within the subject combustor and one or more additional sensors in nearby combustors. Dynamic pressure sensor output signals from the sensors are cross correlated to identify acoustic oscillations generated by a flame in the subject combustor and received by the sensors. The cross correlation may be constrained by a maximum time delay between correlated components of the signals, based on physical characteristics.

A cap for a gas sensor module is described herein. The cap can include at least one wall forming a cavity having a first portion and a second portion. The cap can also include an inlet tube coupling feature disposed in the at least one wall, where the first location is adjacent to the first portion of the cavity. The cap can further include an outlet tube coupling feature disposed in the at least one wall, where the second location is adjacent to the second portion of the cavity. The cap can also include a distribution channel coupling feature disposed in the at least one wall, where the third location is adjacent to the first portion of the cavity. The cap can further include a receiving channel coupling feature disposed in the at least one wall, where the fourth location is adjacent to the second portion of the cavity.

A photoacoustic detection system includes a detector that has a chamber, a pulsed light source, piezoelectric tuning forks, and a photosensor. The chamber has an inlet and an outlet for flow of an analyte. The pulsed light source is adjacent the chamber and is operable to emit a light beam along a path through the chamber. The tuning forks are arranged along the path, and each of the tuning forks is operable to emit first sensor signals. The photosensor is arranged along the path and is operable to emit second sensor signals. A controller is connected to receive the first and second sensor signals. The controller is configured to determine whether a target species is present in the analyte based on the first sensor signals and determine whether the target species is present in the analyte based on the second sensor signals.

A method including providing an acoustic resonator having an absorption element with a surface portion, providing a sample fluid or a fluid mixture containing the sample fluid with at least one absorption fluid or particles such that the acoustic resonator is filled with the same, the surface portion of the absorption element being in contact with the sample fluid. Irradiating the surface portion of the absorption element with a first electromagnetic radiation such that the absorption element at least partly absorbs the first electromagnetic radiation in the region of the surface portion, or irradiating the fluid mixture with a first electromagnetic radiation such that the absorption fluid or the absorption particles at least partly absorb(s) the first electromagnetic radiation, and so, by way of the absorption, pressure energy is generated in the sample fluid or the fluid mixture, with the first electromagnetic radiation being amplitude modulated or frequency modulated with a modulation frequency. Measuring an acoustic response signal from the acoustic resonator. Determining at least one amplitude or phase of the acoustic response signal.