A Carbon Dioxide Detector Used in Earthquake Ruins

Field effect Hydrogen gas sensor devices based on β-Ga2O3 thin films with a function of temperature compensation were fabricated. β-Ga2O3 thin films were deposited on sapphire substrate by gallium evaporation in oxygen plasma. Resistance between two ohmic electrodes on β-Ga2O3 thin film with Pt gate was decreased in H2 ambient. The sensor can detect 100ppm H2 under 20%O2 at 400 o C. The resistance of the device without gate little changes for an ambient variation. By connecting the devices with and without gate in series, the devices have a function of self temperature compensation. It was demonstrated that the device kept stable output even for temperature fluctuation over 100 o C.

The objective of this study was to compare the temperature dependence of a scintillation survey meter with and without the temperature compensation function. Investigation of temperature dependence is important to make precise measurements in various environments. The experiment was conducted using the NaI (Tl) scintillation survey meter with the temperature compensation function (TCS-1172) and the NaI (Tl) and CsI (Tl) scintillation survey meters without the temperature compensation function (TCS-171, PDR-111). In all, 1 cm dose equivalent rate (µSv/h) was measured by changing the room temperature from 10 to 40 degree Celsius. The results showed that the scintillation survey meter with the temperature compensation function had almost no change in the measured values with changes in room temperature, whereas the 1 cm dose equivalent rate of the scintillation survey meter without the temperature compensation function changed by a maximum of -7.2 (%/10°C) as temperature increased. This study confirms that the scintillation survey meter with the temperature compensation function was less dependent on temperature, and stable measurement was possible. However, it was suggested that the scintillation survey meter without the temperature compensation function might cause a drop in the measured value as the temperature rises.

In view of the high incidence of traffic in the road construction, such as highway reconstruction and expansion projects and daily maintenance operations, this paper carried out the research of the high incidence of traffic in the road construction. operations, this paper carried out the research and application of the intelligent warning system against accidental intrusion. The design and development concept of the anti-intrusion system is based on the following principles The design and development concept of the anti-intrusion early warning system is put forward, which is “multi-sensor collaboration - multi-source data fusion - efficient hierarchical early warning - assisting the intruder in the road construction, such as highway reconstruction and expansion projects and daily maintenance operations. efficient hierarchical early warning - assisted intelligent decision”. The early warning system is composed of early warning host, sound and light alarm, alarm shoulder light, water light/yellow light, management, background and other components, which solves the problem of early warning. The early warning system is composed of early warning host, sound and light alarm, alarm shoulder light, water light/yellow light, management background and other components, which solves the technical problems of vehicle collaborative sensing and hierarchical early warning. The system is applied to several highway reconstruction and expansion projects. The application results show that the system can identify dangerous driving vehicles timely and accurately and send dangerous driving information to the vehicle owners. The application results show that the system can identify dangerous driving vehicles timely and accurately and send alarm information to drivers and operators, and the accurate alarm rate reaches more than 90%, effectively The application results show that the system can identify dangerous driving vehicles timely and accurately and send alarm information to drivers and operators, and the accurate alarm rate reaches more than 90%, effectively reducing the incidence of vehicle break-in accidents.

A method based on infrared induction radar is proposed for intrusion sound and light alarms in radiation detection operation sites. We will use infrared sensors to sense the thermal radiation of human bodies or objects within the work site, and monitor specific areas through the constructed infrared light “wall”. When someone or an object enters the preset alert area and blocks the infrared beam, the sensor will quickly detect changes in thermal radiation and monitor and track potential intruders in real time, then trigger the alarm system. The alarm system emits strong sound and light signals through sound and light alarms to deter intruders and notify relevant personnel, ensuring the safety of the work site. The experimental results show that this method has the characteristics of high efficiency, sensitivity, and reliability, and is suitable for radiation detection operation sites and other places that require high safety requirements, effectively improving the level of safety protection.

The micro fluidic chamber with narrow gap for high pressurized fluid has been designed and fabricated. The carbon dioxide (CO2) is injected into the narrow gap spaces of 0.5 μm and 1.6 μm. Their thermal resistance changes have been measured by changing the pressure and temperature. Hence, related to the effect of narrow space the critical pressure of supercritical CO2 is shifted to lower values. When the gap distance is shorter, the pressure of the minimum total-thermal-resistance (R <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">total</sub> ) becomes lower. This "narrow space effect" is enhanced by the shorter gap distance. Additionally, the change of thermal resistance related to pressure change is more responsive for narrower spacing. The smaller spacing seems to make more sensitive responsibility of the inserted fluid property. These results indicate that the filled fluid in a micro-chamber can be applied for the applications of sensing and switching devices using variable physical properties of the packaged fluid in narrow spaces.

Design of Real Time Monitoring System for Dangerous Goods Transportation Based on DSP

Along with the progress of The Times, anti-theft doors and Windows and civil air defense the way it is difficult to meet the needs of the People's Daily to prevent, pyroelectric infrared sensor due to its rapid development, relatively mature and the price is low wait for an advantage, application is more and more widely, based on pyroelectric infrared sensor with single chip microcomputer made home burglar alarm has good prospects for development. This design aims to develop a home anti-theft alarm based on MCU. This design intends to use the STC89C52 microcontroller produced by STC MCU Limited as the core device, in order to achieve the alarm design with infrared home anti-theft function. Because pyroelectric infrared sensor device has the function of detecting human body or animal by emitting infrared ray and converting detection information into corresponding electronic signal, this sensor is used for this alarm. The alarm system supports two different working states: manual emergency alarm state and deployment alarm state. In the state of manual emergency alarm, when the user presses the alarm button, the alarm will immediately sound and light alarm; In the deployment and alarm state, when the user presses the deployment button, the system triggers the sensor to work and monitor the deployment area. When an intruder is found, the sound and light alarm is triggered.

Monitoring of methane gas concentration in the mine is directly related to the safety of coal mine production and lives of the vast majority of miners. Based on the requirement of methane gas monitoring in the mine, an intelligent methane gas alarm based on ADuC812 microcontroller of Analog Device is designed. Besides the traditional functions of concentration display and sound and light alarm, this methane gas alarm has new characteristics of data filter and voice broadcast. It could start up sound and light alarm and voice alarm within 8 seconds when methane concentration in the air is higher than alarm point(1.92V). It insures the high precision of system and functional reliability. By testing at laboratory and running at workshop ,this methane gas alarm has good result in practical implements.

It is required to provide operating and maintenance staff with complete information about all technological processes and engine parameters to ensure efficient and safe operation of medium speed diesel engine. That is why integrated software and hardware systems of centralized control systems should be created, ensuring the integration of data from various sources and applications, into a comprehensive environment of operational control and management in real time. These systems perform the functions of measuring parameters and comparing them with reference values. When the monitored parameters deviate in a predetermined limit, the sound and light alarm and monitoring system of the ship is a trigger, the deviation value is recorded and its time is recorded as well. The basis of integrated software and hardware systems for centralized control are sensors, signal processing elements, display and recording means, and sound and light alarms.

With the development of economy, the investment in laboratory equipment continues to increase, and the work tasks of experiment managers are increasing. After the students finish the experiment, it is difficult to guarantee that each experiment manager can lock the door on time and complete the experiment for the laboratory. When the manager forgets to lock the door or when there is no one in the laboratory, there are special attempts to enter. The article researches and designs a new type of laboratory anti-theft alarm system, which uses the embedded STC89CS2 single-chip microcomputer as the main control chip and adopts heat release As the sensor module, the electric sensor can be used with the sound and light alarm module to realize the sound and light alarm when the user's laboratory is abnormal. The overall system power consumption is small, the concealment is good, the adaptability is strong, the performance is stable, the cost is low, and it can be widely used. It is applied to the laboratory's anti-theft and abnormal situation reminding processing.

With the social development, gas has been widely applied to various aspects of social life. However, the combustible gas has brought us great convenience, but also there is a considerable risk. Based on this, we designed a kind of "prevention" as the characteristics of the combustible gas automatic detection and alarm systems. The system is the choice of technology is mature and low-cost entry-level 52 series microcontroller as the control center, the whole system is divided into classification sensor detection, alarm distinguishes between sound and light alarm, force control bodies of three parts. The system will detect concentrations of flammable gases, scientific classification, for different grades of police intelligence, the appropriate device driver to send a loud sound and light alarm signal. When you reach the highest level but no one to lift the danger, the system will automatically cut off the gas supply to open the ventilation exhaust and other devices to prevent the occurrence of major accidents, to achieve "prevention first, combining prevention and control" of the human and automatic alarm control system. The automatic alarm control system available in the field of gas alarm has been widely used, it has certain extensibility, compatibility, and stability.

This paper proposes a new solar street lamp control system which is composed of photovoltaic cell, controller, battery and load. In this system controller as the key part applies the microchip to achieve many functions. According to the nonlinear output characteristics of solar cell and the influence of environment, it uses the perturbation and observation (P&O) method to realize the maximum power point tracking (MPPT) and promotes the efficiency. In order to prolong the battery life the pulse width modulation (PWM) charge mode is selected to control the battery capacity and provent the battery from the state of over-charge and over-discharge. Meanwhile the function of temperature compensation, charge and discharge protection are set to improve the running safety and stability.Keywordssolar street lamp controllerbatteryperturbation and observation methodMPPTPWM

The infrared sensing information often belongs to the weak signal in the detection system. In order to detect weak infrared sensing signal effectively, the paper designs a detection system scheme and detecting amplified circuit with the function of temperature compensation, and the detecting amplified circuit can effectively suppress the noise. Based on the above, a wavelet multi-scale and multi threshold processing algorithm of weak sensing information is proposed. In order to reduce the problem of signal distortion caused by general threshold de-noising, the paper uses an improved threshold function. In the de-noising process, the soft and hard threshold functions can be chosen flexibly by setting a constant. The experiment results show that the hardware and software signal processing and de-noising methods have good effect on the detection of weak infrared sensing signals.

The results obtained in our experiment are two-fold : Firstly, a convenient model of a near-infrared spectrophotometer, which has proved to be useful in the determination of mellowness in fruit, was successfully applied to the measurement of fat content in horse mackerel and dried split horse mackerel. This measurement may be performed instantly, with the specimen remaining intact. To obtain this result, we used multiple linear regression (MLR) based on second derivative values of spectra measured at the back abdomen side part of the fish body and the fat content of the whole body. This resulted in a good calibration equation, with D2 log(1/R), at the fat band of 924nm, as the first variable. Secondly, we succeeded in developing a global calibration equation that can be used for both frozen and thawed samples of horse mackerel, eliminating the need to measure the temperature of each specimen. The global calibration equation has the function of temperature compensation, with high accuracy : 0.88 decision coefficient (R2) and 1.6% standard error of prediction (SEP) for whole fish (actual fat range 1-24%) and dried split fish (actual fat range 1-19%).

The measurement principle of thermal gas mass flowmeter was explained in the paper. Design of the thermal gas mass flowmeter based on the MSP430 microcontroller. The flowmeter using assembled platinum-film probe as it's sensor, and its flow measuring circuit has the function of temperature compensation. The flow measuring experiment of the flowmeter was tested on Sonic Nozzle. The results of experimental data processing proved that the flowmeter has a wide measuring range, high accuracy and repeatability. The measuring range was 100∶1. From 0.1 Q max to Q max , the relative error was less than ±1.5%