To improve the reliability of the light emitting diode(LED)signal lamp filament current monitoring alarm instrument for metro systems,a new type of hot standby online monitoring apparatus was developed which is based ...To improve the reliability of the light emitting diode(LED)signal lamp filament current monitoring alarm instrument for metro systems,a new type of hot standby online monitoring apparatus was developed which is based on synchronous transmission data(STD)bus technology.In this system,a double hot standby mode can be achieved by adopting bus arbitration.In addition,to detect the effective value of alternating current which is from 0 to 200 mA in the signal lamp lighting circuit,a precision rectifier signal conditioning circuit and an isolated acquisition circuit were designed.This new type of alarm instrument has high detection accuracy and could meet the functional requirements for metro signal systems after comparing it with some industry products that were applied on the spot.展开更多
Geo-technical instrumentation and monitoring is very important for the construction of civil works in urban area, by which the affect or even damage to the existing building and underground utilities in the working si...Geo-technical instrumentation and monitoring is very important for the construction of civil works in urban area, by which the affect or even damage to the existing building and underground utilities in the working site or vicinity caused by construction activities can be predicted. During the construction of Tuen Mun station, West Railway, Hong Kong, series of Geo-technical instruments were installed and monitored in time, and the monitoring data were transferred to the Geo-technical Monitoring System in the headquarter of the Employer promptly. Meanwhile, the alarming data were responded immediately and the modified construction methods have been adopted to avoid the damage to the building and underground utility in working site to ensure the smooth construction of the station.展开更多
文摘To improve the reliability of the light emitting diode(LED)signal lamp filament current monitoring alarm instrument for metro systems,a new type of hot standby online monitoring apparatus was developed which is based on synchronous transmission data(STD)bus technology.In this system,a double hot standby mode can be achieved by adopting bus arbitration.In addition,to detect the effective value of alternating current which is from 0 to 200 mA in the signal lamp lighting circuit,a precision rectifier signal conditioning circuit and an isolated acquisition circuit were designed.This new type of alarm instrument has high detection accuracy and could meet the functional requirements for metro signal systems after comparing it with some industry products that were applied on the spot.
文摘Geo-technical instrumentation and monitoring is very important for the construction of civil works in urban area, by which the affect or even damage to the existing building and underground utilities in the working site or vicinity caused by construction activities can be predicted. During the construction of Tuen Mun station, West Railway, Hong Kong, series of Geo-technical instruments were installed and monitored in time, and the monitoring data were transferred to the Geo-technical Monitoring System in the headquarter of the Employer promptly. Meanwhile, the alarming data were responded immediately and the modified construction methods have been adopted to avoid the damage to the building and underground utility in working site to ensure the smooth construction of the station.