The use of thermocouple sensor DS18B20 digital temperature and humidity and performance are introduced

We all know thermocouple sensor DS18B20 digital temperature and humidity can be applied in various fields, the right using method can provide the performance of the instrument, due to the performance requirements for digital humidity thermocouple sensor is also very high, so the project is to introduce the specific questions about the use and performance of digital temperature and humidity thermocouple sensor is introduced.

thermocouple digital temperature and humidity sensor is the temperature and humidity quantity, physical quantities by temperature, humidity sensor and the corresponding circuit into a convenient data acquisition equipment such as computer, PLC and intelligent instrument directly read digital thermocouple sensor. Thermocouple sensor data output format is likely to be RS232 and RS485 data, a data bus, CAN bus data, ZIGBEE data, TCPIP data and duty ratio data.

host control digital transformation finish temperature and humidity, temperature and humidity thermocouple sensor before each time to read and write, want to undertake reset thermocouple sensor of digital temperature and humidity, and the CPU to the reset request data offline pull 500 mu s, and then release. Digital temperature and humidity thermocouple sensor will wait for 16 - after receiving the signal After about 60 mu s, a 60 - again 240 mu s low pulse. The CPU receives the signal indicates that the reset successfully. In fact, small hardware overhead need relatively complex software to compensate. Due to the thermocouple sensor and digital temperature and humidity between microprocessor adopts serial data transmission method, therefore, in the programming of digital temperature and humidity thermocouple sensor, speaking, reading and writing, must be strictly guaranteed to read and write timing, otherwise, will not be able to read correctly temperature measurement results.

thermocouple for hanging in single bus digital temperature and humidity sensor, the number of people will think thermocouple sensor can hang any number of digital temperature and humidity, and is not the case in practice. If hang on single bus digital temperature and humidity thermocouple sensor exceeds 8, you will need to solve the problem of the bus driver of the microprocessor, therefore, when making battery monomer multi-point temperature measurement system design the questions to pay attention.

to connect digital temperature and humidity of the thermocouple sensor bus cable length limitation. Experiment, when using common signal cable and the transmission length of more than 50 m, read the temperature measurement data error will occur. And take bus cable instead of twisted pair shielded cable, normal communication distance is 150 m, such as belt shielding layer and twisted per meter more twisted-pair cable, the normal communication distance can be extended further. This kind of situation is mainly caused by bus distributed capacitance makes signal waveform distortion, therefore, in the use of digital temperature and humidity thermocouple sensor for temperature measurement system design should fully consider long distance bus distributed capacitance and impedance matching problem.

in the digital temperature and humidity thermocouple sensors measuring temperature programming, when digital temperature and humidity thermocouple sensor to temperature and humidity conversion after the command, program total want to wait for return signal of thermocouple digital temperature and humidity sensor. So, once a digital temperature and humidity thermocouple sensor contact bad or break line, the program read the thermocouple sensor when there is no return signal digital temperature and humidity, so as to make the program into the infinite loop. Therefore, in the digital temperature and humidity thermocouple sensor hardware connection and software design, should be given enough attention.

compared with analog, digital temperature and humidity of thermocouple sensor has many advantages, the anti-interference ability of the thermocouple sensor, signal transmission distance, improve the stability of thermocouple sensor, but also improves the thermocouple sensor integrated precision and reliability, electromagnetic compatibility performance will be much better.

that's project for everyone on the use and performance of digital temperature and humidity thermocouple sensor is introduced, we can according to the above content for reference, hope that the above details can help users better instrumentation, through the above description, we should take more attention on instrument performance.

more high quality thermocouple sensor

key words: thermal resistance, thermocouple, thermal resistance, platinum resistance, PT100, PT1000, pressure thermocouple sensor, digital temperature thermocouple sensor