电化学气体传感器模组说明.doc

ME3-HF Electrochemical SensorManual（Model：ME3-HF）Zhengzhou Winsen Electronics Technology Co., LtdME3-HF Gas SensorME3-HF electrochemical sensor detect gas concentration by measuring current based on the electrochemical principle, which utilizes the electrochemical oxidation process of target gas on the working electrode inside the electrolytic cell, the current produced in electrochemical reaction of the target gas are in direct proportion with its concentration while following Faraday law, then concentration of the gas could be get by measuring value of current.* Low consumption* High precision* High sensitivity* Wide linear range* Good anti-interference ability* Excellent repeatability and stability2 ApplicationWidely used in industrial and environmental protection fields3. Technical Parameter4. External dimension5.CharacterizationFeatures of Sensitivity, response and output signal Data graph of concentration linearity featuresV0 Change upon Variable Temperature Sensitivity upon variable temperature6.Basic circuit7.Anti-Interference:ME3-HF sensor also responds to other gases besides target gas. Below are the response characteristics of interferential gasesGas Concentration ME3-HFCO 200ppm 0ppmSO2 10ppm ≤1ppmCL2 10ppm ≈5ppmHCL 10ppm ≈10ppmCHE 1000ppm 0ppmCH3COOH 100ppm 100ppmC2H5OH 1000ppm 0ppm8.Application Notes:⏹Sensor shall Avoid organic solvent, coatings, medicine, oil and high concentration gases；⏹All ME Sensors shall not be encapsulated completely by resin materials, and shall not immerse inpure oxygen environment, otherwise, it will damage the function of sensor；⏹All ME sensors shall not be applied in corrosive gas environment, or the sensor will be damaged；⏹Please test the sensitivity of gas sensors in clean atmosphere；⏹Sensors Shall be avoided to face the gas, which flow directly from front side；⏹To avoid to bend and break of pins；⏹Blowhole of the sensor should not be blocked and polluted, which will cause the sensitivitydecrease;⏹Excessive impact or vibration should be avoided；⏹Do not use the sensor when the shell is damaged；⏹It takes some time for the sensor to return to normal state After applied in high concentration gas；⏹Do not take apart the sensor, otherwise electrolyte leakage can cause sensor damage;⏹Working electrode and reference electrode of the sensor shall be in short circuit when stored.；⏹To preheat over 48hs before using and soldering forbidden;Note: To keep continual product development, we reserve right to change design features without prior notice！Zhengzhou Winsen Electronics Technology Co., LtdAdd.: NO.299 Jin Suo Road, National Hi-Tech Zone,Zhengzhou, 450001 ChinaTel.: 0086-371-67169097Fax**************E-mail:*******************。

电化学气体传感器的研究电化学气体传感器是由膜电极和电解液灌封而成的.气体浓度信号将电解液分解成阴阳带电离子,通过电极将信号传出。

它的优点是：反映速度快、准确(可用于ppm级)，稳定性好、能够定量检测,但寿命较短(大于等于两年）.它主要适用于毒性气体的检测，目前国际上绝大部分毒气检测采用该类型传感器。

电化学气体传感器的分类电化学气体相当一部分的可燃性的、有毒有害气体都有电化学活性，可以被电化学氧化或者还原。

利用这些反应，可以分辨气体成份、检测气体浓度。

电化学分很多子类：(1）、原电池型气体传感器(也称：加伏尼电池型气体传感器,也有称燃料电池型气体传感器，也有称自发电池型气体传感器)，他们的原理行同我们用的干电池,只是，电池的碳锰电极被气体电极替代了。

以氧气传感器为例，氧在阴极被还原,电子通过电流表流到阳极，在那里铅金属被氧化。

电流的大小与氧气的浓度直接相关。

这种传感器可以有效地检测氧气、二氧化硫、氯气等.(2）、恒定电位电解池型气体传感器，这种传感器用于检测还原性气体非常有效，它的原理与原电池型传感器不一样，它的电化学反应是在电流强制下发生的，是一种真正的库仑分析的传感器。

这种传感器已经成功地用于：一氧化碳、硫化氢、氢气、氨气、肼、等气体的检测之中，是目前有毒有害的主流传感器。

(3)、浓差电池型气体传感器，具有电化学活性的气体在电化学电池的两侧,会自发形成浓差电动势，电动势的大小与气体的浓度有关，这种传感器的成功实例就是汽车用氧气传感器、固体电解质型二氧化碳传感器.(4）、极限电流型气体传感器，有一种测量氧气浓度的传感器利用电化池中的极限电流与载流子浓度相关的原理制备氧（气）浓度传感器，用于汽车的氧气检测，和钢水中氧浓度检测.电化学气体传感器是通过检测电流来检测气体的浓度,分为不需供电的电池式以及需要供电的可控电位电解式。

基于电化学原理工作的传感器其最简单的一种型式就是两电极系统。

其工作电极和对电极由一薄层电解液隔开并经由一个很小的电阻联通外电路。

电化学气体传感器氧气传感器概况所有的氧气传感器都是自身供电，有限扩散，其金属-空气型电池由空气阴极，阳极和电解液组成。

氧气传感器简单来说是一个密封容器（金属的或塑料的容器），它里面包含有两个电极：阴极是涂有活性催化剂的一片PTFE（聚四氟乙烯），阳极是一个铅块。

这个密封容器只在顶部有一个毛细微孔，允许氧气通过进入工作电极。

两个电极通过集电器被连接到传感器表面突出的两个引脚，而传感器通过这两个触角被连接到所应用的设备上。

传感器内充满电解质溶液，使不同种离子得以在电极之间交换（参见图1）。

Figure 1 - Schematic of oxygen sensor.进入传感器的氧气的流速取决于传感器顶部的毛细微孔的大小。

当氧气到达工作电极时，它立刻被还原释放出氢氧根离子：O2 + 2H2O + 4e-4OH-这些氢氧根离子通过电解质到达阳极（铅），与铅发生氧化反应，生成对应的金属氧化物。

2Pb + 4OH-2PbO + 2H2O + 4e-上述两个反应发生生成电流，电流大小相应地取决于氧气反应速度（法拉第定律），可外接一只已知电阻来测量产生的电势差，这样就可以准确测量出氧气的浓度。

电化学反应中，铅极参与到氧化反应中，使得这些传感器具有一定的使用期限，一旦所有可利用的铅完全被氧化，传感器将停止运作。

通常氧气传感器的使用寿命为1-2 年，但也可以通过增加阳极铅的含量或限制接触阳极的氧气量来延长传感器的使用寿命。

毛细微孔氧传感器和分压氧传感器城市技术生产的氧气传感器根据进入传感器的氧气的扩散方式的不同分为两种，一种是在传感器顶部设有一毛细微孔，而另一种设有一层固体薄膜允许气体通过。

细孔传感器测量的是氧气浓度，而固体薄膜传感器测量的是氧气的分压。

细孔传感器产生的电流反映的是被测氧气的体积百分比浓度，与气体总压力无关。

但当氧气压力瞬间发生变化时，传感器会产生一个瞬间电流，如果没有控制好就会出现问题。

同样的问题在传感器受到重复压力脉冲时也会出现，例如进入传感器的气体是抽运式的。

工作原理A氧气传感器氧气传感器采用隔膜式伽伐尼电池工作原理。

这类传感器通常包括具有催化活性的贵重金属阴极，易极化的活泼金属阳极，酸、碱、盐的水溶液、或其它离子导体构成的电解质，密闭外壳，管脚等。

氧气传感器的外壳是一个密闭容器并充满电解液，此密闭容器的顶部有一个毛细微孔，允许氧气通过并进入工作电极。

此时氧气将在传感器内部被电解，导致传感器内部导电离子浓度发生变化。

通过测量流过两电极的电解电流可以准确感知环境中氧气浓度的变化。

在适当的范围内，电解电流与氧气浓度呈良好的线性关系。

氧气在传感器中的电化学过程被描述为：当氧气到达工作电极时，立即如反应（1）被还原成氢氧根离子：O2+2H2O+4e→4OH-（1）这些氢氧根离子通过电解质到达阳极（铅），与铅发生氧化反应（2），生成对应的金属氢氧化物。

2Pb+4OH-→2Pb(OH)2+4e（2）总电池反应：O2+2Pb+2H2O=2Pb(OH)2（3）反应生成的电流大小相应地取决于氧气扩散速度，氧气的扩散速度则取决于氧分压和毛细孔孔径的大小。

可外接一只已知电阻来测量产生的电势差，这样就可以准确测量出氧气的浓度。

电化学反应中，活泼金属铅参与到氧化反应中被不断消耗和钝化，使传感器具有一定的使用期限，当所有可利用的活泼金属铅完全被氧化或钝化时，传感器将停止工作。

通常氧气传感器的预期使用寿命为1-2年，但也可以通过增加阳极铅的含量或限制接触阳极的氧气量来延长传感器的使用寿命。

B毒性气体传感器利用待测气体在电解池中工作电极上的电化学氧化过程，通过电子线路将电解池的工作电极和参比电极恒定在一个适当的电位，在该电位下可以发生待测气体的电化学氧化，由于氧在氧化和还原反应时所产生的法拉第电流很小，可以忽略不计，于是待测气体电化学反应所产生的电流与其浓度成正比并遵循法拉第定律。

这样，通过测定电流的大小就可以确定待测气体的浓度。

通常，三电极电化学式气体传感器主要由电极、电解液、电解液的保持材料、除去干涉气体的过滤材料、密闭外壳，管脚等零部件组成。

Electrochemical GasDetection ModuleUser’s Manual V1.2（Model：ZE12）Valid from:2016-12-28 Zhengzhou Winsen Electronics Technology Co.,LtdStatementThis manual copyright belongs to Zhengzhou Winsen Electronics Technology Co.,LTD.Without the written permission,any part of this manual shall not be copied,translated,stored in database or retrieval system,also can’t spread through electronic,copying,record ways.Thanks for purchasing our product.In order to let customers use it better and reduce the faults caused by misuse,please read the manual carefully and operate it correctly in accordance with the instructions.If users disobey the terms or remove,disassemble,change the components inside of the sensor,we shall not be responsible for the loss.The specific such as color,appearance,sizes…etc.,please in kind prevail.We are devoting ourselves to products development and technical innovation,so we reserve the right to improve the products without notice.Please confirm it is the valid version before using this manual.At the same time,users’comments on optimized using way are welcome.Please keep the manual properly,in order to get help if you have questions during the usage in the future.Zhengzhou Winsen Electronics Technology CO.,LTDElectrochemical Detection Module ZE12ZE10is a general-purpose and high-performance electrochemical module.It can detect the CO 、SO2、NO2、O3based on electrochemical principle,it has good selectivity and stability.Atemperature sensor is built-in for temperature compensation.It has the digital output and analog voltage output at the same time which facilities the usage and calibration and shorten the development period.It is a combination of mature electrochemical detection principle and sophisticated circuit design,to meet customers’different detection needs.FeaturesHigh sensitivity &resolutionLow power consumption &long working life UART,analog voltage and PWM outputGood stability and excellent anti-interference abilityMain ApplicationCity atmospheric environmental monitoring ,enterprise environment monitoring,Factory area unorganized emission monitoring,emergency monitoring,environment evaluation monitoring,Portable gas detector,various gas detection equipment and smart home appliance.Technical ParametersFigure 1:Module chartModel No.ZE12Target Gas CO,H2S,NO2,SO2,O3Preheat time ≤5Min Response time ≤30Sec Resume time ≤30Sec Resolution ≤10ppb Working VoltageDC 5.0V ±0.1V Output DataDAC(0.4～2V)standard voltage signal UART Output(3V level,compatible with 5V)PWM OutputDimension Φ39×44mmWeight75gOperating Environment Temp.:-20～50℃Humidity.:15%RH-90％RH(no condensation)Storage EnvironmentTemp.:-20～50℃Lifespan2year(in air)Pin definitionTable 2.Pin1Vout (0.4～2V)Pin2GND Pin3Vin (Vlotage input)Pin4UART(TXD)data output Pin5UART(TXD)data inputFigure 2:Module bottom viewDetection range and signal outputDetection gas CO H2S SO2NO2O3Detection range 0-12.5ppm 0-2ppm 0-2ppm 0-2ppm 0-2ppm Gas code0x040x030x2B0x2C0x2AConcentration Unit ConversionIn room temperature 25℃,under a standard atmospheric pressure,the measured value [ug/m3]=[ppb]*gas relative molecular mass/air relative molecular mass.E.g.:relative molecular mass of CO is 28,while for air it is 22.4,thus N =28/22.4=1.25.Conversion Factor N=ppb m ug 3/,e.g.:If current concentration of CO is 500ppb,its ug/m3is:1.25*500=625ug/m3.AccessoriesFool-proofing socket (it is necessary to connect user’s pcb board and module,and this accessory has pcb library,see note 7)Communication Protocol1.General SettingsBaud Rate 9600Data Bits 8bytes Stop Bits 1byte check bitsNullmunication SpecificationThe default communication type is active upload and it sends gas concentration every one second.For example,if detect CO,the command line format is like below (Table 4).012345678Start byteGas nameUnit PPBno decimal pointgasconcentrati on(highgasconcentrati on(lowFullmeasurem ent (highFullmeasurem ent (lowCheckvalueDetection gas CO H2S SO2NO2O3Conversion Factor N1.251.5182.8572.0542.143byte)byte)byte)byte)0xFF0x040x040x000x000x000x300XD40XF4Gas concentration value=concentration high byte*256+concentration low bytePlease note that in the above calculation formula,the High byte and Low byte means the decimalism value changed from hexadecimal.Shift to question and answer mode,command line format as below(table5)012345678Start byte Reserve SwitchcommandQuestionandanswerreserve reserve reserve reserve Checkvalue0xFF0x010x780x410x000x000x000x000X46 Switch to initiative upload mode,commands as following(table6).012345678Start byte Reserve SwitchcommandActivelyuploadreserve reserve reserve reserve Checkvalue0xFF0x010x780x400x000x000x000x000X47 Read gas concentration(table7).012345678Start byte Reserve commandReserve reserve reserve reserve reserve Checkvalue0xFF0x010x860x000x000x000x000x000X79 Sensor responses(table8).012345678Start byte Command gasconcentration(high byteug/m3)gasconcentration(low byteug/m3)reserve reserve Gas concentrationhigh byte(ppb)Gasconcentration low byte(ppb)Checkvalue0xFF0x860x000x2A0x000x000x000x200X30 3.Checksum and calculation/***********************************************************************Function Name:unsigned char FucCheckSum(uchar*i,ucharln)*Functional description:Sum check【Take1\2\3\4\5\6\7of sending and receving protocol Non+1】*Function declaration:array[n]NOT﹛Sum（array[1]~array[n-1]）}+1（number of array must be larger than2）**********************************************************************/unsigned char FucCheckSum(unsigned char*i,unsigned char ln){unsigned char j,tempq=0;i+=1;for(j=0;j<(ln-2);j++){tempq+=*i;i++;}tempq=(~tempq)+1;return(tempq);}Cautions●Please do not use the modules in systems which related to human being’s safety.●Please do not use the modules in strong air convection environment.●Please do not expose the modules in high concentration organic gas for a long time.●Sensor shall avoid organic solvent,coatings,medicine,oil and high concentration gases.●Excessive impact or vibration should be avoided,otherwise the value won’t be accurate.●The module should be charged for over24hours for the first time,and supply circuit should beequipped with power reservation function.Otherwise,it will affect continuity and accuracy of returned data if it goes offline for too long.●The module should avoid direct sunlight,and fool-proof socket should be used to fix the module(PCBpackage library info pls contact salesperson).Its peripheral structure needs to be anti-rain,anti-shake and anti-drop from the socket.●When communicate with module,it is recommended to correspond a serial port with a module,thusmake it convenient for later calibration and maintenance.●According to communication protocols,it is necessary to check whether byte0,byte1and checksumare correct after receiving the data,thus to ensure correctness of receiving data frames.●It is suggested to use USB-convert-TTL tools and UART debug assistant software,and observe basedon communication protocols to judge whether module communication is normal.Zhengzhou Winsen Electronics Technology Co.,LtdAdd:No.299,Jinsuo Road,National Hi-Tech Zone,Zhengzhou450001ChinaTel:+86-371-67169097/67169670Fax:+86-371-60932988E-mail:*******************Website:。

· 产品描述· 产品特点7 SMART Sensor Module 传感器模块由电化学传感器和数据采集处理板组成。

传感器为标准7系结构(盛密科技电化学传感器)，数据采集处理板对传感器信号进行放大、采样、滤波，经MCU数据处理后实现气体的检测。

通过配置不同传感器，模块可对环境中存在的各类有毒有害及可燃性气体进行实时浓度检测，方便用户在不同场合下以简洁的方式快速组成系统，适用于室内、室外的空气质量检测，以及工业领域等的气体检测。

· 统一的电气接口、机械尺寸和通讯协议；· 可以根据需求选择不同的传感器，灵活应用于不同的场合；· 模块内置温度、湿度传感器，以及对应的补偿算法，以减小 环境温湿度变化对测量结果的影响；· 多种输出接口，包括USART 、I²C ；· 配置金属外壳 (可选)，具有保护内部电路防尘防水功能；· I²C 地址可编程，方便用户根据需求自定义。

· 技术参数传感器配置：检测原理：测量范围：分辨率：电化学7系电化学传感器测量误差：依所选传感器规格书而定依所选传感器规格书而定依所选传感器规格书而定工作电压：工作电流：信号输出方式：USART (3.3V TTL 电平)(3.2 ~ 5.5) VDC≤ 5 mA @ 5 VI²C (3.3V TTL 电平)安装方式：工作温度：工作湿度：0% ~ 90%RH (无冷凝)11脚插针工作压力：-20°C ~ 55°C1 ± 0.1 标准大气压外壳材质：外形尺寸：重量：30 克铝合金工作寿命：Φ 33.5 x 31 毫米传感器寿命见数据手册电路板寿命5年 (无腐蚀环境下)产品尺寸·引脚定义图·PIN 1PIN 2PIN 3PIN 4PIN 5PIN PIN PIN PIN 6789PIN 10PIN 11所有尺寸标注以毫米为单位除非另有说明，所有公差±0.20毫米俯视图侧视图仰视图·USART 通信协议· 引脚定义5746321NC RX TX GND VCC NC PWR 预留针脚 (悬空)串口输入RX 串口输出TX 电源地电源 (3.2 ~ 5.5 V )预留针脚 (悬空)模块电源使能 (低电平关闭，高电平开启，内置上拉电阻) 默认上拉高电平911810SDA SCL GND VCCI²C 信号SDA (内置10kΩ上拉电阻) 默认上拉高电平I²C 信号SCL (内置10kΩ上拉电阻) 默认上拉高电平电源地电源 (3.2 ~ 5.5 V )注: 两个VCC 信号内部连通1. 串行通信参数起始位：1； 数据位：8； 停止位：1； 校验位：无； 波特率：115200 bps无特殊说明时，应答回复时间小于100ms (特殊情况请参考具体指令说明)，当前命令回复前无法响应其他指令2. 帧格式 (每一通信帧的格式如下)首字节设备码功能码起始地址数据长度数据校验位(高位在前)H ID F A N D CRC16H ：数据头，1Byte 固定为0x3AID ：设备码，1Byte 默认为0x10，可由用户自定义F ：功能码，1Byte ，例如（0x03）A ：起始地址，2Bytes ，例如0x0001N ：数据长度，1Byte ，以2个字节为单位，例如（0x02: 4字节）D ：数据，N*2Bytes ，高位在前，例如（MSB LSB ）定义为有符号短整型（signed short ）CRC16：数据校验，2Bytes ，使用MODBUS_CRC16校验算法（算法详见附录1）3. 指令说明3.1 读取传感器类型上位机发送请求0x3A 0x100x010x00000x010x00000x82B0首字节设备码功能码起始地址数据长度数据校验位例：3A 10 01 00 00 01 00 00 82 B0模块接收正确数据应答首字节设备码功能码数据校验位0x3A0x100x01D(1byte数据）CRC16传感器类型代码 (十进制)：0,1：无定义 2：CO 3：O2 4：H2 5：CH4 6：无 7：CO2 8：O3 9：H2S 10：SO2 11：NH3 12：CL2 13：ETO 14：HCL 15：PH3 16：无 17：HCN 18：无 19：HF 20：无21：NO 22：NO2 23：NOX 24：CLO2 25：无 26：无 27：无 28：无 29: 无 30：无31：THT 32：C2H2 33：C2H4 34：CH2O 35：无 36：无 37：无 38：无 39: CH3SH 40：C2H3CL 例：3A 10 01 0F 4C AD(十六进制0F=十进制15，即得到该传感器为PH3传感器)3.2 读取传感器数据 (单位为μg/m³)上位机发送请求首字节设备码功能码起始地址数据长度数据校验位0x3A0x100x030x00000x020x00000x7352例：3A 10 03 00 00 02 00 00 73 52模块接收正确数据应答首字节设备码功能码起始地址数据长度数据校验位0x3A0x100x030x00000x02D CRC16 D：接收到的数据，4Bytes 高位在前例：3A 10 03 00 00 02 00 00 00 5E 25 35 (D=0x0000005E=94, 得到传感器值为94μg/m³)3.3 读取传感器数据 (单位为ppb)上位机发送请求首字节设备码功能码起始地址数据长度数据校验位0x3A0x100x030x00020x020x00000x72EA 例：3A 10 03 00 02 02 00 00 72 EA模块接收正确数据应答首字节设备码功能码起始地址数据长度数据校验位0x3A0x100x030x00020x02D CRC16 D：接收到的数据，4Bytes 高位在前例：3A 10 03 00 02 02 00 00 00 4C A4 DA (D=0x0000004C=76, 得到传感器值为76ppb)备注：读取数据显示精度为1ppb，具体测试精度根据传感器不同而不同3.4 读取温度传感器数据 (单位为°C)上位机发送请求首字节设备码功能码起始地址数据长度数据校验位0x3A0x100x030x00040x010x00000x8262例：3A 10 03 00 04 01 00 00 82 62模块接收正确数据应答首字节设备码功能码起始地址数据长度数据校验位0x3A0x100x030x00040x01D CRC16 D：接收到的数据，2 Bytes 高位在前，除以100后得到温度值。

红外SF6气体传感器模组说明书V1.0郑州炜盛电子科技有限公司Zhengzhou Winsen Electronic Technology Co.,LTD感谢您使用郑州炜盛电子科技有限公司系列产品，当您准备使用本产品时请务必仔细阅读本说明。

并按照所提供的有关操作步骤进行，使您能充分享受我公司提供的服务。

请妥善保管本手册，以便在您日后需要时能及时查阅、获得帮助。

版权声明：本手册版权属郑州炜盛电子科技有限公司所有，未经书面许可，本手册任何部分不得复制、翻译、存储于数据库或检索系统内，也不可以电子、翻拍、录音等任何手段及方式进行传播。

郑州炜盛电子科技有限公司秉承科技进步原则，不断致力于产品改进、技术创新的服务理念。

在此，本公司保留任何产品改进而不预先通知的权利。

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郑州电子科技有限公司通讯地址：郑州市高新技术开发区金梭路299号邮编：450001服务电话：*************/60932966/60932977传真号码：*************微信号：winsensor服务信箱：*******************目录1概述 (4)2技术参数 (5)3.结构尺寸图（单位：MM） (6)4.信号输出 (6)5安装尺寸图（单位：MM） (11)6维护保养应注意的事项 (11)1概述SF6气体作为绝缘介质和灭弧气体在电力设备普遍使用，特别在高压断路器、变压器、互感器、电容器、避雷器、熔断器等有广泛应用。

发生泄漏，设备压力降低,绝缘能力降低；污染和破坏大气环境，增加温室效应；在低层空间积聚，导致工作人员大脑缺氧，甚至快速窒息等事故；局部放电、高温等因素影响下，SF6气体会产生如SF4、SF2、SOF2等高毒分解物。

此产品是一款采用NDIR红外吸收检测原理的气体传感器模组，根据SF6气体在10.5um的吸收量确定浓度大小。

RevisionFormaldehyde Sensor ModuleDescriptionCB-HCHO the forth generation formaldehyde sensor is an electrochemical gas concentration sensor. It adopts a dual-channel structure design and unique electrolyte packaging technology. With optimized algorithm and scientific calibration, it can simultaneously output formaldehyde and TVOC. Built-in digital temperature and humidity sensors combined with intelligent algorithms, product detection is more accurate.Working PrincipleWhen formaldehyde gas passes through the sensor, theformaldehydemoleculesundergooxidation-reduction reaction on the electrode to form an electron transfer under the catalytic action of the electrolyte. This reaction produces a small current, which is proportional to the concentration of the gas present, and output the serial signal through the signal amplifying circuit.FeaturesHigh sensitivity up to 1ppb HCHO, VOC in-one designFull range temperature and humidity compensationUnique dual-channel design, good anti-interference, alcohol cross-interference is less than 1%Multiple communication methods ：URAT 、IIC 、PWMLifetime can reach 6 years (in air)ApplicationsPortable instrumentDesktop air quality monitoring equipment Air Purifier HVAC system Air ConditionerSmart HomeTable 1 SpecificationsFormaldehyde sensor specificationsOutline Structure and Interface DefinitionFigure 1: Interface and Connector DefinitionTable 2: Pin Definition TableNo. Pin Description 1 NC Floating 2 PWM PWM Output 3 GND Power input (Ground) 4 VCC Power input (+5V) 5 RXD Signal receiver 6 TXD Signal output 7NCFloatingSensor DimensionFigure 2: CB-HCHO（Forth Generation) Appearance dimension drawing (unit: mm, tolerance±0.2mm)Communication Protocol1. General Statement1) The data in this protocol is all hexadecimal data. For example, “46” for decimal [70].2) [xx] is for single-byte data (unsigned, 0-255); for double data, high byte is in front of low byte.3) Baud rate: 9600; Data Bits: 8; Stop Bits: 1; Parity: No2. Format of Serial Communication ProtocolSending format of upper computer：Detail description on protocol format：3. Command Table of Serial Protocol4. Content of Protocol4.1 Read formaldehyde concentration commandSend：11 01 01 EDResponse：16 0D 01 DF1-DF2 DF3-DF4 DF5-DF6 DF7-DF8 DF9-DF10 DF11-DF12 [CS]Response Description：1. HCHO concentration value = （DF1*256 + DF2）/1000 (Unit: ppm)2. VOC concentration value = （DF3*256 + DF4）/1000 (Unit: ppm）3. Temperature value = （DF5*256 + DF6）/10 (Unit: ℃)4. Humidity value = （DF7*256 + DF8）/10 (Unit: %)5. TVOC concentration value = （DF9*256 + DF10）/1000 (Unit: ppm)6. Sensor Status byte = DF11 Sensor Status byte7. Auto calibration switch byte = DF12 Auto calibration switch byteAuto calibration switch byte4.2 Auto-calibration Setting commandSend：11 02 03 DF1 [CS]Response：16 02 03 DF1 [CS]Response Description：1. DF1 = 00，HCHO manual calibration2. DF1 = 01，HCHO auto-calibration3. DF1 = 02，HCHO calibration value zero clearingRemark:1. The auto-calibration is off as default2. When auto-calibration is set open, the sensor needs to be continuously powered on. When the sensor is power off, and powered on again, the auto-calibration is closed by default.Notice1. When using a formaldehyde sensor module, try to ensure that the test environment temperature, humidity and air velocity remain stable. An unstable environment will cause the sensor's display value to fluctuate.2. The operating temperature range of the formaldehyde sensor module is 10 ~ 50℃, and the relative humidity is 15% ~ 95%. High temperature and low humidity environment will reduce the service life of the module.3. The best storage environment for formaldehyde sensor module is: temperature -20 ~ 60℃, relative humidity is 15% ~ 95%, the storage environment air need to be clean, no dust, no pollution gas, no organic solvent.4. During the long-term transportation of the formaldehyde sensor module, try to ensure that the temperature is within 50°C and the maximum temperature does not exceed 60°C.5. Avoid contact with organic solvents (including glue, anti-paint, washing water and other substances that may emit high concentrations of organic gases) for the formaldehyde sensor module. These uncertain concentrations of gases may exceed the sensor's tolerance range, resulting in sensor poisoning.6. If the formaldehyde sensor module is exposed to high-concentration gas for a short time, it may cause a short-term failure of the sensor (the failure time is related to the concentration and duration of the contacting gas). The sensor must be placed in a clean, ventilated environment and left to be recovered. The recovery time may be Up to 1-2 days.7. If the formaldehyde sensor module is left in high concentration organic gas for a long time, it may cause irreversible damage to the sensor.8. When testing the accuracy of the formaldehyde sensor module, avoid the interference of other gases on the sensor and cause the error of the result to increase.9. When testing the accuracy of the formaldehyde sensor module, it is recommended to use a method of heating volatile paraformaldehyde powder or formaldehyde solution. The maximum concentration must not exceed 1ppm, and the formaldehyde concentration increase rate is less than 0.2ppm / min. If the formaldehyde concentration increase rate is too fast, it will cause sensor errors. (Considering that the rapid volatilization of high concentrations of formaldehyde does not occur in the daily application environment).10. When multiple formaldehyde sensor modules are tested in the same closed environment, after volatile formaldehyde, you can first turn on the fan and stir for 3-5 minutes, then turn off the fan and let it stand for 1-2 minutes to ensure uniform concentration in the environment.11. The formaldehyde sensor module (HCHO V0.3) can identify the interference of low-concentration alcohol (0-7ppm), especially when the concentration is stable; when the alcohol concentration is unstable, the sensor value may be disturbed (less than 0.05ppm), When the concentration is stable, the interference will be automatically eliminated.After-sales Services and ConsultancyTel：86-27-8162 8827Add：Fenghuang No.3 Road, Fenghuang Industrial Park, Eastlake Hi-tech Development Zone, Wuhan, 430205, ChinaZip：430205Fax：86-27-8740 1159Website：E-mail：******************.cn。