This is a greenhouse ecological parameters measurement and control system, the system implements the data collection of field temperature, humidity and carbon dioxide by using the 1-wire bus network which consist of 1...This is a greenhouse ecological parameters measurement and control system, the system implements the data collection of field temperature, humidity and carbon dioxide by using the 1-wire bus network which consist of 1-wire bus temperature sensor, 1-wire bus humidity sensor, Analog-to-Digital Converter（ADC）, CO2 sensor and intelligent battery monitor.展开更多
The fiber Bragg grating （FBG） sensing technology was used to monitor the situation of a crevice of the continuous beam joint and rails near rail expansion devices on a viaduct of the urban railway. The monitoring it...The fiber Bragg grating （FBG） sensing technology was used to monitor the situation of a crevice of the continuous beam joint and rails near rail expansion devices on a viaduct of the urban railway. The monitoring items consisted of the rail temperature, rail displacement, viaduct beam displacement, and strain of sliding rail in the rail expansion device section. The strain sensor was a prefabricate FBG strain gauge, the displacement sensor with different scales used an FBG stress ring, and the FBG of the temperature sensor was pre-drawn and fixed in a metal tube. Compensation sensors were used to balance environmental temperature changes. All FBGs were suspended adhered, therefore the chirped phenomenon of the FBG reflection peak was avoided, and the measurement accuracy was improved. The monitoring results matched to the manual test and theoretical estimation.展开更多
文摘This is a greenhouse ecological parameters measurement and control system, the system implements the data collection of field temperature, humidity and carbon dioxide by using the 1-wire bus network which consist of 1-wire bus temperature sensor, 1-wire bus humidity sensor, Analog-to-Digital Converter（ADC）, CO2 sensor and intelligent battery monitor.
文摘The fiber Bragg grating （FBG） sensing technology was used to monitor the situation of a crevice of the continuous beam joint and rails near rail expansion devices on a viaduct of the urban railway. The monitoring items consisted of the rail temperature, rail displacement, viaduct beam displacement, and strain of sliding rail in the rail expansion device section. The strain sensor was a prefabricate FBG strain gauge, the displacement sensor with different scales used an FBG stress ring, and the FBG of the temperature sensor was pre-drawn and fixed in a metal tube. Compensation sensors were used to balance environmental temperature changes. All FBGs were suspended adhered, therefore the chirped phenomenon of the FBG reflection peak was avoided, and the measurement accuracy was improved. The monitoring results matched to the manual test and theoretical estimation.
