Thermocouple automatic verification system research and dynamic correction release time: 2019 - 02 - Number 13 reading: 12 times

Temperature is an important parameter in heat treatment, in the commonly used several kinds of thermal components, thermocouple is the most widely used, the number is the largest. With the improvement of product process requirement, the quality of the thermal components also need to improve accordingly. Because of this, the thermocouple calibration system performance put forward higher request, also greatly increase the measurement personnel's work strength. Thermocouple automatic verification system based on the demand and also arises at the historic moment, the verification system of various kinds of brands. But the usage of these systems are not very ideal, mainly manifested in two aspects: one is not very ideal; temperature adjustment, control, Second, automation degree is not high, man-made factors. The existing verification system on the market are mostly considered is improved from the aspects of temperature control table, in order to improve the performance of the system. Of course, from the perspective of hardware to improve the precision of temperature control can improve system performance. But this is not only greatly increase the development costs of the system, and the performance index of some equipment are difficult to improve. Also have to consider using all kinds of control algorithm ( Such as genetic algorithm, fuzzy algorithm, neural network, the AT parameters self-tuning) Regulation of temperature, but these algorithms not easy implementation, and control effect remains to be proved. The status quo of the thermocouple calibration system at present and the insufficiency, proposed the thermocouple automatic verification system based on kingview. The system is mainly composed of calibration furnace, sensors, multi-channel switch, high precision digital instrument, thyristor power meter, D/A converters, operational amplifier circuit and A microcomputer control system. Considering the thermocouple junction by heat, basic level test of the compressor with thermocouple, in order to ensure the accuracy of measurement, in addition to from aspects such as the selection of its structure and accidentally silk to take measures, before use should be in static correction, thermocouple for air speed is greater than a certain value, but also for the dynamic calibration of thermocouple. Around the purpose is to consider the thermocouple in the boundary layer exists kinetic energy into heat energy conversion process, determine the total temperature recovery coefficient of thermocouple. According to the formula, when 0 & lt; Air velocity & lt; 30 m/s, assuming Δ T = temperature 30 ℃, the temperature of the thermocouple recovery coefficient gamma = 90%, if not for dynamic calibration, the temperature measurement of the relative error is 0. 14%; When the total 30 thermocouple temperature recovery coefficient changes with the change of the Mach number. Usually require a total of thermocouple temperature recovery coefficient and stability, high sensitivity of flow Angle is not big, so it's best to choose a shield of thermocouple. The thermocouple should be used in calibration in advance on the wind tunnel dynamic correction, and calibrated thermocouple should be used in basic level are measured under the Mach number of correction, to ensure the accuracy of measurement of model level. Beijing instrument huashi technology co. , LTD. Is committed to the industrial production process control instrumentation and automation system development, development, production, sales and engineering construction of comprehensive enterprise, its products are widely used in petroleum, chemical, electric power, metallurgy, brewing industry, water conservancy, environment protection, etc. Company since its inception, has always been to revitalize national industry as own duty, in the unremitting exploration and practice, has brought together a group of senior engineer and expert team, for the thermocouple, heat resistance, and other products has a very rich experience. We have our own products, will also continue to work hard to develop new products, we have our own field, will also have the confidence to have the ability to explore new areas, of course, the general customers trust and support of the company is the foundation of our development, to the greatest extent to meet the different needs of users is the only goal we pursue.