Design and Simulation of a Wireless SAW–Pirani Sensor with Extended Range and Sensitivity

Pressure is a critical parameter for a large number of industrial processes. The vacuum industry relies on accurate pressure measurement and control. A new compact wireless vacuum sensor was designed and simulated and is presented in this publication. The sensor combines the Pirani principle and Surface Acoustic Waves, and it extends the vacuum sensed range to between 10−4 Pa and 105 Pa all along a complete wireless operation. A thermal analysis was performed based on gas kinetic theory, aiming to optimize the thermal conductivity and the Knudsen regime of the device. Theoretical analysis and simulation allowed designing the structure of the sensor and its dimensions to ensure the highest sensitivity through the whole sensing range and to build a model that simulates the behavior of the sensor under vacuum. A completely new design and a model simulating the behavior of the sensor from high vacuum to atmospheric pressure were established

SAW-Pirani vacuum sensor with extended range and sensitivity

In this abstract, a micro wireless vacuum sensor is presented to be operated between high vacuum and atmospheric pressure. The sensor combines the Pirani principle and Surface Acoustic Waves

Correction: Design and Simulation of a Wireless SAW–Pirani Sensor with Extended Range and Sensitivity

The authors wish to make the following erratum to Reference [...

Design and Simulation of a Wireless SAW–Pirani Sensor with Extended Range and Sensitivity

Pressure is a critical parameter for a large number of industrial processes. The vacuum industry relies on accurate pressure measurement and control. A new compact wireless vacuum sensor was designed and simulated and is presented in this publication. The sensor combines the Pirani principle and Surface Acoustic Waves, and it extends the vacuum sensed range to between 10−4 Pa and 105 Pa all along a complete wireless operation. A thermal analysis was performed based on gas kinetic theory, aiming to optimize the thermal conductivity and the Knudsen regime of the device. Theoretical analysis and simulation allowed designing the structure of the sensor and its dimensions to ensure the highest sensitivity through the whole sensing range and to build a model that simulates the behavior of the sensor under vacuum. A completely new design and a model simulating the behavior of the sensor from high vacuum to atmospheric pressure were established

Evaluation of the impact of annealing on gelatinisation at intermediate water content of wheat and potato starches: A differential scanning calorimetry and small angle X-ray scattering study

The DSC (differential scanning calorimetry) thermograms of wheat and potato starches at 50% (w/w) water content are characterised by two gelatinisation endotherms. Two separate phenomena coinciding with the two DSC endotherms can be distinguished in the SAXS patterns of 50% (w/w) suspensions of wheat and potato starches during heating from 25 to 95 °C at 2 °C/min: an increase in peak integral in the temperature domain of the first (G) endotherm and a marked decrease in peak integral in the temperature domain of the second (M1) endotherm. One- and two-step annealing affect only the G endotherm, leading to a shift to a higher temperature of up to 8 °C, sharpening of the peak and an increase in enthalpy, while the completion temperature of the M1 endotherm remains unchanged. Static SAXS measurements indicate that the repeat distances of crystalline and amorphous lamellae in wheat (105 Å) and potato (99 Å) starch granules are unaffected by annealing. One- and two-step annealing intensify the SAXS peaks. The most striking difference between the SAXS gelatinisation profiles of native and annealed starches is that there is no increase in peak integral at the onset of gelatinisation of annealed starches. The effects following annealing are interpreted as a decreased water absorption during gelatinisation. Annealing leads to a retardation of the initial swelling and cooperative melting of the granules, without altering the stability of the most perfect crystallites

Spirit Distillation: Monitoring Methanol Formation with a Hand-Held Device

Methanol occurs naturally in most alcoholic distillates. Yet, suitable detectors to check liquor adherence to legal limits and, most importantly, monitor in situ methanol content during distillation are not available. Usually, distillers rely on error-prone human olfaction while “gold standard” liquid or gas chromatography (GC) are rarely used being off-line, time-consuming, and expensive. Here, we explore monitoring the methanol concentration during industrial distillation of cherry, apple, plum, and herb liquor (196 samples) with a low-cost and hand-held detector combining a Pd-doped SnO2 sensor with a packed bed separation column of Tenax TA. Therein, individual methanol concentrations (0.1–1.25 vol % or 153–3266 g methanol per hectoliter of pure ethanol) are quantified rapidly (within 2 min), bias-free and with high precision (i.e., 0.082 vol %) by headspace analysis, as confirmed by GC. Most importantly, methanol levels above E.U. and U.S. legal limits were recognized reliably without interference by much higher ethanol contents (5–90 vol %) and aromas. Also, the detector worked well even with viscous and inhomogeneous mash samples containing fruit pulp. As a result, this device can help consumers, legal authorities, and distillers to check product safety, guide distillation, and monitor even fermentation to possibly prevent occupational methanol exposure.ISSN:2692-194