Now showing items 1-10 of 10
Improved Tuning Fork for Terahertz Quartz-Enhanced Photoacoustic Spectroscopy
(MDPI AG, 2016)
We report on a quartz-enhanced photoacoustic (QEPAS) sensor for methanol (CH₃OH) detection employing a novel quartz tuning fork (QTF), specifically designed to enhance the QEPAS sensing performance in the terahertz (THz) spectral range. A discussion of the QTF properties in terms of resonance frequency, quality factor and acousto-electric transduction ...
New approaches in quartz-enhanced photoacoustic sensing
We report on the design and realization of custom quartz tuning forks with different geometries and sizes aimed to improve the photoacoustic effect in quartz-enhanced photoacoustic (QEPAS) sensor systems. A detailed analysis of the piezoelectric properties in terms of resonance frequencies, quality factors, gas damping was performed.
Quartz-Enhanced Photoacoustic Spectroscopy: A Review
A detailed review on the development of quartz-enhanced photoacoustic sensors (QEPAS) for the sensitive and selective quantification of molecular trace gas species with resolved spectroscopic features is reported. The basis of the QEPAS technique, the technology available to support this field in terms of key components, such as light sources and ...
Pure amplitude and wavelength modulation spectroscopy for detection of N2O using a three-sections quantum cascade laser
We report on a novel quantum cascade laser (QCL) capable of operating in pure amplitude or wavelength modulation configuration thereby allowing the acquisition of background-free gas absorption-line profiles using quartz-enhanced photoacoustic spectroscopy (QEPAS). The QCL is composed of three electrically independent sections: Gain, Phase (PS) and ...
Low power consumption quartz-enhanced photoacoustic gas sensor employing a quantum cascade laser in pulsed operation
We report here an analysis of the performance of a quartz-enhanced photoacoustic (QEPAS) system operating in a pulsed mode by employing a quantum cascade laser (QCL). The QEPAS system is based on a quartz tuning fork (QTF) having fundamental resonance frequency of 4.2 kHz and a first overtone resonance of 25.4 KHz. Water vapor was used as a target ...
Single-tube on beam quartz-enhanced photoacoustic spectrophones exploiting a custom quartz tuning fork operating in the overtone mode
We report here on the realization of a single-tube on-beam quartz-enhanced photoacoustic (QEPAS) spectroscopy sensor employing a custom-made quartz tuning fork (QTF) with a large prong spacing. The prongs of the QTF have been designed in order to provide a quality factor twice higher when the QTF operates in the first overtone flexural mode than in ...
Quartz Enhanced Photoacoustic Spectroscopy Based Trace Gas Sensors Using Different Quartz Tuning Forks
A sensitive trace gas sensor platform based on quartz-enhanced photoacoustic spectroscopy (QEPAS) is reported. A 1.395 μm continuous wave (CW), distributed feedback pigtailed diode laser was used as the excitation source and H2O was selected as the target analyte. Two kinds of quartz tuning forks (QTFs) with a resonant frequency (f0) of 30.72 kHz and ...
Application of Micro Quartz Tuning Fork in Trace Gas Sensing by Use of Quartz-Enhanced Photoacoustic Spectroscopy
A novel quartz-enhanced photoacoustic spectroscopy (QEPAS) sensor based on a micro quartz tuning fork (QTF) is reported. As a photoacoustic transducer, a novel micro QTF was 3.7 times smaller than the usually used standard QTF, resulting in a gas sampling volume of ~0.1 mm3. As a proof of concept, water vapor in the air was detected by using 1.39 μm ...
Acoustic Detection Module Design of a Quartz-Enhanced Photoacoustic Sensor
This review aims to discuss the latest advancements of an acoustic detection module (ADM) based on quartz-enhanced photoacoustic spectroscopy (QEPAS). Starting from guidelines for the design of an ADM, the ADM design philosophy is described. This is followed by a review of the earliest standard quartz tuning fork (QTF)-based ADM for laboratory ...
Improving the Signal to Noise Ratio of QTF Preamplifiers Dedicated for QEPAS Applications
The signal-to-noise ratio (SNR) is a major factor that limits the detection sensitivity of quartz-enhanced photoacoustic spectroscopy (QEPAS) sensors. The higher the electrical signal level compared to the noise amplitude is the lower the concentration of gases that can be detected. For this reason the preamplifier circuits used in QEPAS should be ...