The performance of a new generation of temperature meter automatic verification device I. Overview With the rapid development of electronic technology, computers and its software technology, instrumentation and its testing technologies have undergone fundamental changes. Traditional measurement theories and measurement techniques and methods can no longer meet the needs of development. New test systems are being computerized. , standardization and network development. Harbin Yuda Electronic Technology Co., Ltd. produces automatic moisture analyzer, moisture meter, moisture monitor, moisture meter. A new generation of thermometer verification devices has been created at the Beijing Zhonghang Institute of Electrical Engineering. It is different from the automatic thermocouple thermal resistance automatic verification device popular in the current market. Under the premise of strict implementation of the ITS-90 temperature scale and national verification procedures, it has achieved a practical multi-purpose machine, and can also complete the task of intelligent measurement management . It is a new generation of temperature meter verification device integrating modern measurement technology, computer measurement and control technology and information management technology. It is a new concept of temperature measurement management system. Second, system composition, performance and principle (a) Basic composition The basic components of the device include multi-functional high-precision digital electronic measuring instruments for core components, multi-channel automatic scanning switches for key components, temperature control systems for major components, and computer printers and supporting software for powerful systems. Through the control circuit and multi-channel interface, the intelligent functions are connected into a system network. (II) Main Performance Indicators Basic function 1 using a standard platinum rhodium 10-platinum thermocouple thermometer to test the second standard platinum rhodium 10-platinum thermocouple thermometer; 2 Verification of industrial thermocouples of various types (S, R, B, K, N, E, J, T) using a standard or second-class standard thermocouple thermometer; 3 Verification of working thermal resistance (Pt100, Pt10, Cu100, Cu50) thermometers using the second standard thermal resistance thermometer; 4 Time-sharing verification of multi-path temperature signal input; 5 Temperature field testing of industrial heat treatment furnaces. 2. Main indicators 1 The accuracy of the digital voltmeter is 0.003% and the resolution is 0.01μV. 2 Scanning switch parasitic potential ≤ 0.4μV. 3 The accuracy of temperature control is 0.1% FS. Stability: ≤0.1°C/min for high temperature furnaces; ≤0.04°C/10min for oil (water) tanks. 4 The thermocouple resistance thermometer for industrial use can test 1~7 times at a time. 5 test temperature range: thermocouple thermometer is 300 °C ~ 1600 °C; thermal resistance thermometer is 0 ~ 300 °C (also Pt100 in -100 °C ~ 0 °C test); liquid thermometer -30 °C ~ 150 °C; 6 The temperature field test range for the heat treatment furnace is 50°C~1000°C. 7 Total Uncertainty: Second-class standard test is 0.5°C Industrial thermocouple test is 0.7°C Thermal resistance test for work is 50mk Heat treatment furnace temperature field test is 1°C 8 Software: Powerful, integrated measurement control and management, providing a complete set of test software for the verification of the establishment of the device. (three) working principle The device comprises a plurality of temperature control loops and a detection loop, respectively. The temperature control loop realizes dual temperature control of temperature and constant temperature software and hardware for high temperature furnaces, oil and water tanks through intelligent temperature control instruments and upper computer instructions. The temperature control loop consists of a temperature sensor and its power control system. The detection loop transmits the signals transmitted by each temperature field to the high-precision intelligent electrical measuring instrument one by one through multiple automatic scanning switches to measure and collect data through a computer. Its working principle is shown in Figure 1. Third, the verification device features and key technologies The guiding ideology for the sake of the user is reflected in the overall design of the verification device, and it can be effectively used for multiple purposes. Second-class standard platinum crucible 10-platinum thermocouple thermometer and industrial thermometers are combined into one; a set of measurement systems can face signals transmitted from multiple constant temperature fields to maximize the use efficiency of the device; this is a feature one. Make full use of modern advanced computer and software technology, use highly reliable general-purpose intelligent temperature control instrument, achieve dual temperature control of hardware and software, improve the reliability and flexibility of the device, is a signal provided by multiple temperature field can use a The basis of the measurement loop; this is the second feature. The third feature is the use of high-precision intelligent multi-function electrical measuring instrument and intelligent low-parasitic multi-channel scanning switch, providing hardware support for a multi-purpose machine. The device can also be completely separated from the PC control, through the manual operation of the various intelligent components (panel operation keys), to achieve semi-automatic work, to ensure that without the upper computer control can continue to carry out the verification work. The realization of the above characteristics is dependent on the close cooperation of hardware and software technologies. Cross-checking in software is the key to implementing a set of measurement systems that can handle signals sent from multiple temperature fields. Through the steady state identification of the signal sent, and then discharge timing, time-sharing measurement, because each measurement of a signal sent from a temperature field in just a few minutes to complete the cycle of data acquisition tasks required by the regulations, and then The measurement of the signal sent from another constant temperature field can be carried out. With the corresponding support on the hardware, the verification of the signal transmitted by multiple temperature fields can be realized. The use of dual hardware and software temperature control is a key measure to increase the temperature of each temperature field as required. The temperature control and constant temperature of each temperature field can ensure that each temperature field enters the constant temperature state and the stabilization time only under the unified command of the upper computer. The intelligent temperature controller itself solves the independent temperature control function without the command of the upper computer. This allows the host computer to time-control the temperature of each temperature field. The dual hardware and software temperature control also further enhances the flexibility, reliability, and stability of the temperature control system. It truly achieves no overshoot and no undershoot. Smooth temperature control effect. High-accuracy electrical-side instruments (6-digit display or 7-digit display) and low parasitic potential automatic scanning switches are the prerequisite for the verification of the second-class standard thermocouple thermometer and the detection of industrial thermocouples. According to the requirements of the respective verification procedures, the corresponding software shall be compiled. The entire system shall be automated except for bundling the thermocouple and installing the furnace (slot). The operator completes the parameter setting at the prompt of the verification software. After the start-up operation, the entire verification system is in a completely automatic working state. Each intelligent component is completely placed under the control of the PC, and the circuit automatically completes the self-test and starts the temperature control according to the program. The system is heated to a constant temperature. When the temperature is stable and meets the requirements of the regulations, data measurement and acquisition, data processing, and data storage are automatically completed and a result file is automatically formed. Until the certificate is printed, the operator only needs to click the mouse according to the prompts. Taking a working thermocouple thermometer test as an example, when the temperature field enters the verification point (static deviation ±5°C) and the furnace temperature fluctuates into a stable temperature field within 0.2°C/min, the microcomputer tests the thermocouples and multiplexes them. The switches turn on in sequence: The device measurement management database and management software are prepared according to the management content requirements, similar to the formulation of the whole plant measurement technology management, measurement and administrative management systems, plans and the establishment of instrumentation account, and has a practical, flexible and convenient query and output functions, can be different Retrieval of plant-wide temperature instrument information, such as retrieval by calibration date, verification personnel, etc., automatic prompting for output of expired meters, printout of verification result data, certificates, etc., as well as statistical calculations for expirations within one week and one month Instruments, etc. provide the basis for advanced "conditional overhaul" and information on the use of on-site thermometers. Multi Function Pipe End Forming Machine Multi Function Pipe End Forming Machine,Roll Grooving Machine,Pipe Flanging Machine,Automatic Roll Grooving Machine Zhangjiagang heshun machinery manufacturer co.,ltd. , https://www.hsformer.com
Each temperature point must have more than two cycles of test data for each thermocouple. If the furnace temperature fluctuates beyond 0.25°C during the test, the test result is invalid (no disk is saved). When the furnace temperature stabilizes again Retest. At this point, the program is switched to scanning tests on signals sent from other temperature fields so that signals from other constant temperature fields can be measured. If there are more than four temperature field input signals, the measurement loop will almost always be in measurement operation. After a setpoint is verified, it is automatically transferred to the next setpoint to increase temperature and constant temperature. The above verification process is repeated until the final temperature point of each temperature field is verified. The verification of the temperature field is automatically stopped and automatically cut off. Heating power supply.