Temperature transmitter is a kind of on-site instrument for contact temperature measurement, which can be used in conjunction with measuring elements to convert temperature or temperature difference signals into unified standard signal output, and other process parameters that can be converted into DC millivolt signals can also be transformed into corresponding unified standard signal output to realize the display of temperature parameters. Display, record and automatic control. Any secondary instrument or PLC, DCS control system with its response can be used to accurately measure the temperature of various media or objects in the process of production tasks. The temperature transmitter is sealed with silicone rubber or epoxy resin, so it is shock-resistant, moisture-resistant and suitable for use in harsh field conditions.
The characteristics of temperature transmitter: the reliability and stability of the instrument have been improved by using the integrated operational amplifier with low drift and high gain; the linearization circuit has been set up in the thermocouple and thermoresistor temperature transmitter, which makes the linear relationship between the output signal of the transmitter and the measured temperature, improves the accuracy of the transmitter, and It is convenient to indicate and record; the safety spark explosion-proof measure is adopted in the circuit, adding the DC/AC/DC converter part, which has the function of safety grating, so it can measure the DC millivolt signal and temperature signal from dangerous places; it can be directly installed in the junction box of the sensor, output the signal accurately and electrically. Flow signal can be transmitted over a long distance of 1 km through twisted pair, which has high anti-interference performance and low maintenance cost. Integrated temperature transmitter and split temperature transmitter have been widely used in different industries.
The choice of temperature transmitter needs attention from different industries and measurement media, such as: the difference of temperature drift: besides the basic accuracy, there are also some factors affecting the accuracy of the instrument, such as the change of working environment which causes the instrument precision to decline. This influence is called the temperature drift of the instrument. This influence is an important indicator of the instrument. The smaller the temperature drift, the higher the measurement accuracy of the instrument, and the less affected by the environmental temperature changes. If the temperature transmitter and the temperature digital display have the same temperature drift index. However, when working, the temperature rise of the temperature measuring digital display instrument is greater than that of the temperature transmitter, so the influence of temperature drift of the temperature transmitter on the total accuracy of the instrument is far less than that of the temperature measuring digital display instrument.
The difference of service life: The service life of 4-20mA two-wire temperature transmitter is much longer than that of temperature measuring digital display instrument. The power supply of temperature measuring digital display instrument is heated badly, and it is easy to fail.
The difference in accuracy is that the accuracy of temperature transmitter is 0.1%, while that of digital display meter is usually 0.5%. Obviously, the accuracy of temperature transmitter is 5 times higher than that of digital display meter.
The difference of electricity cost: the electricity cost of temperature transmitter is less than one-tenth of that of temperature measuring digital display instrument, and it is estimated that each temperature measuring digital display instrument saves about 40 degrees of electricity per year.
Difference in price: Generally, the price of temperature transmitter is higher than that of temperature measuring digital display instrument, but the temperature measuring digital display instrument must be installed in the field with a protective box, and in order to meet the protection requirements and to see the value clearly, only transparent glass can be added, which also increases a lot of costs. Integrated temperature transmitter 24VDC Power supply can be supplied and transmitted through the signal line. Digital display meter is not a two-wire instrument. It needs an independent 220V power supply. Then it has to pull a power line from the remote control room and install safety measures such as air switch. The overall cost is not low, but it has increased a lot.
The difference between installation, use and maintenance is that the terminal of temperature transmitter is less than that of temperature measuring digital display instrument, and it is convenient to install and maintain, so it greatly reduces labor cost and capital cost.
Baoji Baishide Control Technology Co., Ltd.
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