Search

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 development of carbon nanotube (CNT)‐based sensors remains an active area of research. Towards this end, a new method for manipulating CNTs, assembling CNT networks and fabricating CNT‐based nanosensors was demonstrated in this study. CNTs were collected and concentrated by optically‐induced dielectrophoresis (ODEP) forces and aligned between a pair of electrodes. This assembly was then used directly as a temperature sensor and a hot‐film anemometer, which detects changes in windspeed. By offering efficient CNT collection and ready‐to‐use sensor fabrication, this ODEP‐based approach presents a promising method for the development of CNT‐based sensing applications and massively parallel assembly of CNT‐lines. The developed CNT‐based nanosensors may be used to measure the temperature and the flow velocity of bio‐samples in the near future. [ABSTRACT FROM AUTHOR]

A thin film of silica aerogel has been spin coated on silicon wafers to investigate its super thermal insulating capability. The temperature of the thin film heaters fabricated on the aerogel coated wafer is measured at different applied powers. Simulations are performed to compare the aerogel coated wafers with the micromachined wafers. Both experimental and simulation results show better heat insulation for aerogel coated wafers as compared with simulated micromachined wafers. The measurement and simulation results of aerogel coated wafers are in good agreement. The aerogel film can replace the air cavity created by conventional micromachining of wafers to save power and chip area in metal oxide gas sensor arrays. [ABSTRACT FROM AUTHOR]