共查询到19条相似文献,搜索用时 328 毫秒
1.
基于nRF24E1和DS18B20的无线测温系统 总被引:2,自引:1,他引:1
针对目前温度采集系统对数据无线传输、多点采集的需求,提出了基于无线收发芯片nRF24E1的短距离无线多点温度测量系统.系统以射频收发芯片nRF2401为核心,采用数字式温度传感器DS18B20精确测温,实现了短距离无线传输和多点温度数据的采集,并将数据发送至上位机,实现了温度数据的存储、显示、查询等功能.实践结果表明:该系统能够应用在多种温度测量领域,单点测温误差在±0.5 ℃以内,室内发射距离约30 m. 相似文献
2.
通过远程无线多点实时监控的方法完成对工厂、企业以及实验室等存放有毒气体(一氧化碳)的监测,以无线传输测量数据的方式显示并监控有毒气体的浓度,当有毒气体泄漏或浓度超标时,可自动发出警报,打开换气扇,直至切断电源.防止有毒气体泄漏导致对公共场合造成的污染以及对人体的损伤.整个系统采用12V电池电源供电,单片机负责各点数据的接收、并控制存储、处理,最后显示和打印,控制过程可无人看守,节省了人力物力.在程序处理上采用了"插值修正法"并同时引入"自动休眠模式",可使系统在保证测量精度的同时使功耗降到最低.该装置可扩展性好,通过更换其它类型的气敏探头可满足对不同气体的测控需要. 相似文献
3.
土壤电导率测量系统开发 总被引:1,自引:0,他引:1
介绍一种基于“电流一电压四端法”的土壤电导率测量系统的开发。该测量系统由传感器单元、数据采集器USB2808和计算机软件等部分组成。传感器单元包括4个电极,2个外侧电极用来向土壤中输入交流恒流激励信号,2个内侧电极用来检测与土壤电导率相关的电压降。数据采集器USB2808用来将传感器测得的模拟电压信号转换为数字电压信号。计算机软件使用VC++来开发人机交互界面,实现了输入恒流值、内侧电极电压降、土壤电导率等值的显示,并可将这些值保存到数据库中。试验结果表明该测量系统可以有效输出土壤电导率的值。 相似文献
4.
5.
6.
《仪表技术与传感器》2021,(4)
针对生活及工业中对水质纯度的需求,设计了一种基于电导率测量的水纯度检测系统。传感探头采用四环电极结构,可防止因为电极的电容效应和极化效应所带来的影响,提高准确度。探测头后侧金属壁内置Pt100温度传感器,进行温度采集和补偿。该系统用FPGA和AD9708实现波形频率可调输出,作为系统激励信号源。设计了差分电路接收传感器输出信号,并通过调理电路和滤波电路得到关键的幅值信息,通过A/D采集后传输给上位机,进行数据的分析处理。测试结果表明,该系统能够实时测量电导率,电导率测量的相对误差低于0.6%,具备较高的实用价值。 相似文献
7.
基于Zigbee技术的无线测控系统 总被引:5,自引:0,他引:5
在研究Zigbee协议标准的基础上,对无线测控系统进行了分析,提出了基于Zigbee技术与总线技术结合的无线远程测量控制系统架构.设计了单元测控系统的软硬件,实现了信号的获取与无线传输.系统可完成对现场设备的实时数据采集、远程无线数据传输与监控等功能,同时为解决分散点测控与移动点测控布线困难开辟了可行的途径. 相似文献
8.
9.
10.
11.
We use in this paper advanced geophysical techniques for the characterization and monitoring of subsurface properties such
as porosity, water content and electrical conductivity of water. Ground Penetrating Radar (GPR) and electrical conductivity
measurements were recorded monthly during one year at the border of a corn field. Velocity analyses of multioffset GPR data
were conducted to determine total porosity and to monitor vertical transport of water from the soil surface to the water table.
The use of novel and original techniques for GPR processing (GPR velocity estimation by the Common Reflection Surface (CRS)
method, kriging applied to GPR velocity) improved the estimate and the resolution of GPR velocity maps compared with the classical
Normal MoveOut (NMO) and the bi-linear interpolation. Electrical resistivities were used to determine the effective porosity.
The combination of GPR and electrical data permitted to estimate the electrical conductivity of water and to highlight high
conductivity zones, possibly due to contamination by agricultural fertilizers. Independent determinations (grain size fractions,
electrical conductivity, major ion content of water samples and porosity) were obtained, that validate our geophysical investigation.
This study demonstrates the efficiency of non destructive geophysical approaches for providing accurate models of water content,
porosity and electrical conductivity of water down to a depth of several meters in a poorly conductive soil. 相似文献
12.
13.
针对目前动车组轴端加速度监测装置体积较大、质量较重,读取数据不方便,各装置之间的数据同步性较低等缺陷,设计了基于STM32的动车组轴端加速度监测装置。该装置由硬件系统和软件系统构成。硬件系统主要由采集处理主机、压电式加速度传感器组成,其中采集处理主机主控芯片为STM32F407;软件系统由嵌入式软件系统和上位机组成,嵌入式软件系统采用RT-Thread实时操作系统,上位机采用QT框架开发,用于显示加速度数据的频域特征。行车实验表明:监测装置可以对动车组轴端加速度进行实时监测,读取数据方便、设备稳定性较好。校准实验表明:监测装置监测到的加速度误差小于5%,具有较高的精度。 相似文献
14.
15.
研究了纯铜多道次反复镦压剧烈塑性变形后的组织、力学性能及导电性能。结果表明,通过反复镦压能在保持试样原始形状和尺寸的情况下在材料内部累积很大的应变,实现材料组织的超细化,退火纯铜经B路线15道次反复镦压变形后,晶粒细化至亚微米级。随镦压次数的增加,纯铜的硬度和抗拉强度明显提高,抗拉强度达到459.1MPa,伸长率明显下降,但仍在20%以上。纯铜的导电率随镦压次数的增加而下降,但15道次镦压后仍然保持在91.7%IACS,说明反复镦压剧烈塑性变形工艺可以制备出具有高强度和良好导电性的块体纯铜材料。 相似文献
16.
《Measurement》2014
Electrical capacitance tomography (ECT) is an imaging technique commonly used for imaging dielectric permittivity of insulating objects. In applications such industrial process tomography and non-destructive testing (NDT), the objects under test may exhibit variations in both dielectric permittivity and electrical conductivity. In particular, a sample that includes high conductivity, such as metal, can cause a large change in electrical field in ECT. The metal sample in imaging area will cause a large change in the sensitivity map of ECT compared to free space, which will make the ECT image reconstruction inaccurate. This effect is more severe in grounded conductor than floating conductors, so this paper focuses on grounded conductor. In order to update the sensitivity map, one needs to gain information about the conductivity distribution in ECT problem. Magnetic induction tomography (MIT) is sensitive to electrical conductivity and not sensitive to permittivity variations; therefore, it can be used to visualize the conductivity distribution of the target under test. In this paper, a dual-modality MIT and ECT system is proposed to image a medium including conductors and dielectrics. Both simulated and experimental results are presented, which demonstrate the feasibility of the proposed method. 相似文献
17.
近年来,对高速高刚度数控机床用电主轴的需求日益紧迫。采用陶瓷材料设计电主轴主要旋转部件可以提高电主轴极限转速及刚度。但由于陶瓷材料导热、导磁及导电及机械性能与金属材料差别较大,因此陶瓷电主轴电磁振动与金属电主轴有所不同。研究陶瓷电主轴电磁振动有利于实现电主轴的低噪声低振动优化设计。本文通过实验研究了陶瓷电主轴的电磁振动特性。 相似文献
18.
《Measurement》2014
The variety of methodologies used to determine the electrical conductivity of carbons makes it very difficult to compare samples and establish reference values. In this study, the electrical conductivity of a wide range of carbons was determined using two different methods: four-point probe and compression. Although the methodologies and the operating conditions are very different, linear correlations between the values measured by these two methods can be established for some of the materials studied. Only materials with a very high conductivity (graphite and carbon black) could not be correlated. 相似文献
19.
设计了一种柔性次品剔除系统.该系统包括多气缸的气压装置和PLC控制装置,设计出了柔性次品剔除装置的基本结构,并分析了它的工作原理;同时给出了气压控制系统的控制回路及其电气原理图.通过实际项目的研究表明,该系统能够完成自动化生产线上次品剔除,并且不会对分离的次品造成损坏. 相似文献