共查询到18条相似文献,搜索用时 156 毫秒
1.
2.
3.
随着当前人们对家居、小区及企业等防盗防入侵需求的日益提高,安防报警系统得到广泛应用。超声波探测器、热释电红外探测器、微波探测器等这些单一技术的报警探测器都会受到环境干扰而影响探测性能,导致增加了误报率。本文介绍的热释电红外微波复合的探测器把微波和红外感应探测技术运用在一体,相互弥补了这两种感应探测技术的不足,提高了实际探测的可信度并减少了误报率。现今,手机已经成为人们随身携带的通讯工具,基于此,本项目设计了一种应用热释电红外微波复合的探测器和应用GSM模块与手机通信的基于ATmega16的低成本高效安防报警系统。 相似文献
4.
5.
介绍一种小区物业安全防盗报警系统的硬件结构组成及工作原理,提出了采用热释电探测器加无线DF模块进行多点的监测集中反映到值班室,进行统一管理的新方法. 相似文献
6.
7.
8.
9.
针对环境监测和工业现场对有害气体浓度精确监测的需要,利用红外吸收光谱检测原理,以DSP芯片TMS320F2812为控制处理核心,设计了能同时检测CO、C02、CH4浓度的有害气体监测系统。简要说明了红外吸收光谱检测原理及系统架构,详细介绍了脉冲调制红外光源、热释电红外探测器、信号调理电路、智能控制处理系统的设计。实验结果表明,该监测系统测量精度高、稳定性能好、具有较高的应用推广价值。 相似文献
10.
11.
The method and the experimental setup of a trap pyroelectric detector calibration against the BNM-INM Cryogenic Radiometer, at three laser wavelengths in the visible range were investigated. With this study, we have extended the absolute sensitivity measurements of the electrically calibrated trap pyroelectric detector (trap EPD) over 350–1850 nm range by spectroscopic reflectivity measurements. With our method, the relative standard uncertainty associated to the wedging factor was less then 0.4% (coverage factor, k = 1). 相似文献
12.
13.
The linearity of a pyroelectric detector used for pulsed laser energy absolute measurement has been studied using an experimental evaluation. Two different methods were used to evaluate the detector linearity: by comparison to a calorimeter and using the inverse square distance law. Different detection substrates were used and tested. A heating material in the form of a thin film was integrated into the substrate. This material is not only absorbent to transform laser energy into heat but also electrically resistive to transform the electric energy delivered by a current pulses generator into heat by Joule effect. An original approach based upon an electric substitution method has been used to measure the pulses energy given by the laser system and not the pulses mean power as it is commonly used. The measurement method is then based upon the comparison of the maximum voltage responses which are proportional to the pulse energy. 相似文献
14.
王丽芳 《计算机工程与应用》2012,48(9):208-210,241
在锥束工业CT系统中,通常要求射线源焦点、物体旋转中心、平板探测器中心三点在一条直线上,与平板探测器垂直。由于机械的定位误差,探测器定位后会出现一定角度的倾斜现象,如果直接利用平板探测器倾斜后采集的投影数据进行重建,重建结果将会出现偏离,产生伪影。针对该问题,利用系统标定的方法测得探测器倾斜角度,利用机械校正对其进行粗调,利用提出的基于探测器倾斜的FDK修正算法进行微调,经过两次校正可以有效抑制由于平板探测器倾斜造成的伪影,通过实验验证了该方法的可行性。 相似文献
15.
《Sensors and actuators. B, Chemical》2000,62(1):13-22
In microcalorimetry for measuring heats of adsorption on clean single-crystal surfaces, a pulse of gas from a molecular beam adsorbs on an ultrathin single crystal's surface, causing a measurable transient heat input and temperature rise. One new and sensitive method of heat detection uses a 9 μm pyroelectric polymer ribbon, which is mechanically driven to make a gentle mechanical/thermal contact to the back of the single-crystal sample during measurement (J.T. Stuckless, N.A. Frei, C.T. Campbell, A novel single-crystal adsorption calorimeter and additions for determining metal adsorption and adhesion energies, Rev. Sci. Instr. 69, 1998, 2427–2438). Here we describe simulations of the signal pulse shape and an analysis of absolute signal intensities, based on system parameters such as the detector pyroelectric coefficient and thermal conductivities of the detector and sample, in order to understand heat collection efficiency in this and related calorimetric techniques. 相似文献
16.
17.
设计了一种能够在一次测量中完成同一方向上多个目标测距的系统。该系统利用数字匹配滤波器的捕获功能,实现多个回波的捕获,多用户检测器对捕获进行处理;利用比相器得到测距的到达时间差,从而完成了同一方向上的多个目标测距。与传统测距相比,多目标测距可以在一次测距过程中,对测距范围和测距方向上出现的多个目标同时进行测量,从而大大提高了测距系统的实用性和灵活性。 相似文献
18.
为了提高食品、工业环境中毒性物质的检测水平和响应时间,设计了一种基于生物发光法的毒性检测仪。该检测仪以生物发光法作为检测手段,利用毒性物质会抑制荧光素强度的原理,通过检测荧光素的强度来计算毒性物质的毒性。实际试验结果表明,系统能有效的监测到荧光的强弱,可快速准确的计算出待测物质的毒性,且响应快速,响应时间仅为30ms;测量精度相对较高,相对误差小于5%。 相似文献