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This study reports an insightful portable vector network analyser (VNA)‐based measurement technique for quick and selective detection of Hg2+ ions in nanomolar (nM) range using homocysteine (HCys)‐functionalised quartz‐crystal‐microbalance (QCM) with cross‐linked‐pyridinedicarboxylic acid (PDCA). The excessive exposure to mercury can cause damage to many human organs, such as the brain, lungs, stomach, and kidneys, etc. Hence, the authors have proposed a portable experimental platform capable of achieving the detection in 20–30 min with a limit of detection (LOD) 0.1 ppb (0.498 nM) and a better dynamic range (0.498 nM–6.74 mM), which perfectly describes its excellent performance over other reported techniques. The detection time for various laboratory‐based techniques is generally 12–24 h. The proposed method used the benefits of thin‐film, nanoparticles (NPs), and QCM‐based technology to overcome the limitation of NPs‐based technique and have LOD of 0.1 ppb (0.1 μg/l) for selective Hg2+ ions detection which is many times less than the World Health Organization limit of 6 μg/l. The main advantage of the proposed QCM‐based platform is its portability, excellent repeatability, millilitre sample volume requirement, and easy process flow, which makes it suitable as an early warning system for selective detection of mercury ions without any costly measuring instruments. [ABSTRACT FROM AUTHOR]

To diagnose the running state of bushing and avoid serious power grid accidents, online multi‐parameter monitoring equipment for dissolved hydrogen, oil pressure and temperature in bushing oil was developed. The equipment includes three units: signal acquisition, control cabinet and data analysis. A new hydrogen sensor without oil–gas separation membrane and based on palladium alloy film technology was developed. A three‐in‐one sensor for hydrogen, oil temperature and pressure monitoring has been developed, which has the advantages of miniaturisation, lightweight and easy installation. Test results show the hydrogen measurement range of the sensor is 0–5000 ppm, and the accuracy can reach 10% or 15 ppm (with larger values). The pressure measurement range is 0–1.0 MPa, the resolution is 0.1 kPa, and the accuracy can reach 0.25 grade. The temperature measurement range is −40 to 105°C, and the accuracy is ±1°C. The measurement performance of the device fully meets the requirement of online monitoring of transformer bushing. The equipment has been put into operation in a 330 kV substation, which can monitor the bushing status online and help eliminate the early latent fault of bushing in the weak budding state. [ABSTRACT FROM AUTHOR]

The authors report quartz crystal microbalance (QCM) integrated with hexagonal boron nitride–graphene (hg) monolayer heterostructure as a sensor to detect mass flow of sulphur hexafluoride (SF6), an important electrical insulating gas, under humid conditions. Their recent work demonstrated an enhancement in QCM sensing characteristics upon attaching monolayer 2D materials onto the QCM electrode surface and its application for improved relative humidity measurement. Here, they extend this approach to detect flow of SF6 gas causing variation in relative humidity. They fabricated a hg-QCM sensor by transferring the heterostructure thin film onto the QCM electrode surface using a standard wet transfer technique and measured return loss of the QCM under SF6 gas flow at a selected RH condition. The mass flow of the humid SF6 gas effects perturbation in damping at the QCM surface as indicated by changes in the motional resistance of the QCM. The motional resistance changes introduced significant variation in loaded Q-factor, the magnitude of which was gas species-dependent, thus allowing to distinguish SF6 from other common electronics gases. [ABSTRACT FROM AUTHOR]