A non-dispersive photoacoustic gas detector includes an infrared light source, a first closed chamber, a first acoustic sensor in fluid communication with the first closed chamber, a second closed chamber, and a second acoustic sensor in fluid communication with the second closed chamber. The first closed chamber comprises a plurality of windows that are substantially transparent to infrared light from the infrared light source. The second closed chamber comprises at least one window that is substantially transparent to infrared light from the infrared light source, and the first closed chamber is arranged in series with the second closed chamber between the infrared light source and the second closed chamber.

A non-dispersive photoacoustic gas detector includes an infrared light source, a first closed chamber, a first acoustic sensor in fluid communication with the first closed chamber, a second closed chamber, and a second acoustic sensor in fluid communication with the second closed chamber. The first closed chamber comprises a plurality of windows that are substantially transparent to infrared light from the infrared light source. The second closed chamber comprises at least one window that is substantially transparent to infrared light from the infrared light source, and the first closed chamber is arranged in series with the second closed chamber between the infrared light source and the second closed chamber.

A radiation detector for a non-dispersive infrared gas analyzer has two detector chambers, which are surrounded by a housing and separated by a separating element permeable to infrared radiation and impermeable to gas and which can be filled with a radiation-absorbing measurement gas. A receiving element, which has a measuring system fastened therein and including a flow- or pressure-sensitive sensor, can be attached to a contact surface on an outer face of the housing. Each detector chamber is pneumatically connected to the measuring system by a channel, which extends in the housing and is open to gas. The housing of the radiation detector is modularly constructed and includes a base element, which encloses the channel, the separating element, and the measuring system fastened in the receiving element, and a first and a second outer element, each of which can be connected to the base element and surrounds a detector chamber. The outer elements have openings, which lie in the beam path of the infrared radiation and are sealed in a gas-tight manner by a radiation-permeable window. The receiving element and the first and the second outer elements are joined to the base element.

A radiation detector for a non-dispersive infrared gas analyzer has two detector chambers, which are surrounded by a housing and separated by a separating element permeable to infrared radiation and impermeable to gas and which can be filled with a radiation-absorbing measurement gas. A receiving element, which has a measuring system fastened therein and including a flow- or pressure-sensitive sensor, can be attached to a contact surface on an outer face of the housing. Each detector chamber is pneumatically connected to the measuring system by a channel, which extends in the housing and is open to gas. The housing of the radiation detector is modularly constructed and includes a base element, which encloses the channel, the separating element, and the measuring system fastened in the receiving element, and a first and a second outer element, each of. which can be connected to the, base element and surrounds a detector chamber. The outer elements have openings, which lie in the beam path of the infrared radiation and are sealed in a gas-tight manner by a radiation-permeable window. The receiving element and the first and the second outer elements are joined to the base element.

The infrared gas analysis device includes: a measurement cell to allow a sample gas containing a component to be measured to flow therethrough; a comparison cell including a reference gas; a pair of light sources provided in one end side of the measurement cell and the comparison cell, the cells being irradiated with an infrared ray from one and the other of the light sources, respectively; and a detection unit provided in another end side of the measurement cell and the comparison cell to detect the component to be measured by using infrared rays output from the measurement cell and the comparison cell. A gas for detection made of a component different from the component to be measured and having an infrared absorption band at at least a part of wavenumbers in infrared absorption bands of the component to be measured is encapsulated in the detection unit.

Gas detector devices, systems, and methods using a Golay cell are described herein. One device includes a microphone having a front surface with a sound collecting aperture for receiving sound, a substrate, a gas cavity formed in the substrate such that the gas cavity is in gas communication with the sound collecting aperture and the front surface forms a side surface of the gas cavity, and a window abutting the substrate to form a side surface of the gas cavity.

The infrared gas analysis device includes: a measurement cell to allow a sample gas containing a component to be measured to flow therethrough; a comparison cell including a reference gas; a pair of light sources provided in one end side of the measurement cell and the comparison cell, the cells being irradiated with an infrared ray from one and the other of the light sources, respectively; and a detection unit provided in another end side of the measurement cell and the comparison cell to detect the component to be measured by using infrared rays output from the measurement cell and the comparison cell. A gas for detection made of a component different from the component to be measured and having an infrared absorption band at at least a part of wavenumbers in infrared absorption bands of the component to be measured is encapsulated in the detection unit.

Gas detector devices, systems, and methods using a Golay cell are described herein. One device includes a microphone having a front surface with an sound collecting aperture for receiving sound, a substrate, a gas cavity formed in the substrate such that the gas cavity is in gas communication with the sound collecting aperture and the front surface forms a side surface of the gas cavity, and a window abutting the substrate to form a side surface of the gas cavity.

Gas detector devices, systems, and methods using a Golay cell are described herein. One device includes a microphone having a front surface with an sound collecting aperture for receiving sound, a substrate, a gas cavity formed in the substrate such that the gas cavity is in gas communication with the sound collecting aperture and the front surface forms a side surface of the gas cavity, and a window abutting the substrate to form a side surface of the gas cavity.

Gas detector devices, systems, and methods using a Golay cell are described herein. One device includes a microphone having a front surface with an sound collecting aperture for receiving sound, a substrate, a gas cavity formed in the substrate such that the gas cavity is in gas communication with the sound collecting aperture and the front surface forms a side surface of the gas cavity, and a window abutting the substrate to form a side surface of the gas cavity.