|信息来源： 液位变送器生产 | 2020-10-15 点击量： 1380|
3151 / 3051 vertical pipe differential pressure densimeter is an automatic instrument for on-line measurement of density of various liquids or liquid mixtures. It is a field instrument for continuous on-line measurement of liquid density, which can be directly used in industrial production process. The intelligent on-line densitometer adopts advanced technology, including a capacitive high-precision differential pressure sensor and a pair of pressure repeaters connected to it and inserted into the production process. There is a temperature sensor between the two pressure repeaters to compensate for the temperature change of the process liquid. 3151 / 3051 vertical pipeline differential pressure densimeter can measure liquid density continuously and on line without process interruption. It can be directly used for the control of the production process; it adopts the integrated two-wire transmitter structure, no moving parts, easy to install, use and maintain; equipped with cleaning device, the probe can be cleaned regularly to ensure the use accuracy.
The accuracy is determined by nonlinearity, hysteresis, non repeatability, temperature, zero offset scale, and temperature effect. But mainly by the pressure transmitter nonlinear, hysteresis, non repeatability, the higher the accuracy, the higher the price. Each kind of electronic geometer will have accuracy error, but because the accuracy level of each country is different, for example, the accuracy of national standards such as China and the United States is the best part of the sensor's linearity, that is, the accuracy between 10% and 90% of the measurement range as we usually call it; while the accuracy of European standard is the worst part of linearity, In other words, we usually say that the accuracy of the measurement reverse is between 0% and 10% and 90% to 100%. If the accuracy of European standard is 1%, the accuracy of Chinese standard is 0.5%.
The products can be widely used in the petrochemical industry for the detection of oil, oil refining, oil blending and oil-water interface detection; in the food industry, it is used for the processing of grape juice, tomato juice, fructose syrup, vegetable oil and soft drinks; the dairy industry; the paper industry; the measurement of black pulp, green pulp, white pulp and alkali solution; the accuracy of wine making; the chemical urea, detergent, ethylene glycol, acid-base and polymer density Degree measurement. It can also be used in mining brine, potash, natural gas, lubricating oil, biopharmaceutical and other industries.
Measurement range: 0.000 – 3.000g/cm3 (0000 – 3000kg / m3) (users can choose the measurement range at will)
Calibration range: 0.500 – 3.000g/cm3 (500 – 3000kg / m3) (calibrated according to the measurement range selected by users)
Measurement accuracy: ± 0.01g/cm3, ± 0.005g/cm3, ± 0.002g/cm3 (user's choice of applicable accuracy)
Repeatability: ± 0.0005g/cm3 (± 0.5kg/m3)
Operating temperature range: - 50 ℃ ~ + 250 ℃ (different medium temperatures can be selected, including low temperature, normal temperature and high temperature)
Maximum working pressure: 7.0Mpa
Fluid viscosity range: 0 – 20000 CP
Temperature coefficient: less than 0.1kg/m3 / ℃ (after correction)
Pressure effect: negligible
Built in temperature sensor: PT1000
Contact material: 316L, Hastelloy C-276, tantalum, titanium, polytetrafluoroethylene (Teflon)
It is impossible to calibrate the smart transmitter with the above conventional method, because it is determined by the structure and principle of Hart transmitter. Because the intelligent transmitter between the input pressure source and the generated 4-20mA current signal, in addition to mechanical and electrical circuits, there is also a microprocessor chip for input data operation. Therefore, the adjustment is different from the conventional method.
In fact, the manufacturer also has instructions for the calibration of intelligent transmitter. For example, for the transmitter of 3151 / 3051 vertical pipeline differential pressure densimeter, there are "set range", "reset range" and "fine adjustment". The "set range" operation is mainly through the LRV.URV The "pressure source" is directly connected to the "pressure source" to set the working pressure. However, the initial and final setting of the range directly depends on the actual pressure input value. However, it should be noted that although the relationship between the analog output of the transmitter and the input value used is correct, the value displayed by the digital reading of the process value will be slightly different, which can be calibrated by adjusting the term. Since each part needs to be adjusted separately and jointly, the actual calibration can be carried out according to the following steps:
1. Make a 4-20mA fine adjustment to calibrate the D / a converter inside the transmitter. Since it does not involve sensing components, there is no need for external pressure signal source.
2. Make another fine adjustment in the whole process to make the 4-20mA digital reading consistent with the actual pressure signal, so the pressure signal source is needed.
3. Finally, rerange and adjust the analog output 4-20mA to match the external pressure signal source. Its function is exactly the same as the zero (z) and range (R) switches on the transmitter shell.
Huaheng Xi'an transmitter manufacturer adopts diversified business ideas. While producing and operating industrial automation instruments and devices, it also has outstanding achievements in instrument control system integration, complete set of instruments and equipment, installation, commissioning and maintenance services, technical training and consulting. The representative projects include the kinetic energy control system of glass sintering in rainbow group and the technical transformation of boilers in Hanjiang pharmaceutical industry.
Huaheng Xi'an transmitter manufacturers rely on professional and technical advantages, reliable and stable product quality, adhere to the maximum meet the needs of users is the power source of enterprise development, with high-quality professional services for China's electric power, petroleum, chemical, metallurgy, cement, mining, municipal, papermaking and other industries to provide high performance price ratio of industrial automation instrument products. It is important for the development of automation instrument in China