Development Trend of Intelligent Temperature Sensor
Since the 21st century, intelligent Temperature Sensor is to high-precision, multi-function, bus standardization, high reliability and security development, the development of virtual Temperature Sensors and network Temperature Sensors, the development of single-chip temperature measurement system and other high-tech direction of rapid development.
1.1 intelligent Temperature Sensor to improve the temperature accuracy and resolution: the first launch of intelligent Temperature Sensor, the temperature accuracy is low, the resolution can only reach 1 ° C. At present, China has introduced a variety of high-precision, high-resolution intelligent Temperature Sensor, using 9? 12 A / D converter, the resolution is generally up to 0.5? 0.0625 ° C. Developed by the United States DALLAS semiconductor company new DS1624 high-resolution intelligent Temperature Sensor, can output 13 binary data, the resolution up to 0.03125 ° C, the temperature accuracy of ± 0.2 ° C
1.2 intelligent Temperature Sensor to improve multi-channel conversion speed: In order to improve the multi-channel intelligent Temperature Sensor conversion rate, some chips also use high-speed successive approximation A / D converter. To AD7817 5-channel intelligent Temperature Sensor, for example, in the local sensor, each remote sensor conversion time is only 27us, 9us. In addition, the intelligent Temperature Sensor from single channel to multi-channel direction, which is to develop and develop multi-channel temperature measurement and control system to create the conditions.
1.3 intelligent Temperature Sensor to increase the versatility: the versatility of the new intelligent Temperature Sensor is also increasing.
Temperature Sensors Thermal sleeves are used to protect Temperature Sensors such as thermocouples, thermistors and bimetallic thermometers to prevent overpressure, material speed and corrosion damage. They also increase the life of the sensor, allowing the sensor to replace, without draining the system and reducing the possibility of contamination. Thermal sleeves designed for high pressure applications are usually machined to ensure integrity. Smaller thermal sleeves for low-pressure environments can be made of welded pipes at one end.
All temperature sensing devices are susceptible to exposure to flow, heat and pressure. As time goes by, harsh machining environments can affect sensor performance and structural integrity. For example, the metal used to make thermocouple probes is susceptible to corrosive environments. In addition, the diameter of the thermocouple wire is typically between 0.10 and 0.20 ", and prolonged exposure to heat will undergo metallurgical changes, and the thermocouple casing protects the measurement sensor from the destructive effects of the process environment, thereby preventing measurement drift. All temperature data should be recorded on a recording device such as a temperature controller, etc. In addition, any Temperature Sensor used in these processes should be periodically calibrated to verify accuracy. The dry block probe calibrator is a thermistor, thermocouple, and RTD The NSC traceability is available for non-contact devices such as thermal imagers and pyrometers. Infrared blackbody calibrators offer 1% accuracy, but repeatability. Calibration can be performed indoors. The certified AS17025 calibration laboratory will ensure The method used can be traced back to NIST.
The Temperature Sensor type consists of two different wires connected at two points. The change in voltage between these two points reflects the proportional change in temperature. Thermocouples are non-linear and need to be converted for temperature control and compensation, usually using the lookup table. Low accuracy from 0.5 to 5 ° C. However, they operate over the widest temperature range from -200 to 1750 ° C.