How to choose the right pressure transmitter and installation and use precautions - Database & Sql Blog Articles

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How to choose the right pressure transmitter and installation and use attention, the correct selection of pressure transmitter should be analyzed according to the following factors

1. Confirm the type of measurement pressure

Pressure types mainly include gauge pressure, absolute pressure, and differential pressure. Gauge pressure refers to the pressure based on the atmosphere, less than or greater than atmospheric pressure; absolute pressure refers to the absolute pressure zero as the benchmark, higher than the absolute pressure; differential pressure refers to the difference between the two pressures.

2. Confirm the pressure stroke

Under normal circumstances, the actual measurement pressure is selected as 80% of the measurement range.

3, confirm the measurement pressure introduction

According to the different measuring medium, it can be divided into dry gas, gas liquid, strong clothing liquid, viscous liquid, high temperature gas liquid, etc. According to the accurate selection of different media, it is beneficial to prolong the service life of the product.

4. Confirm the maximum overload of the system

The maximum overload of the system should be less than the overload protection limit of the transmitter, otherwise it will affect the service life of the product or even damage the product. The CYB series has an overload pressure of twice the full scale.

5, confirm the correctness level

The measurement error of the transmitter is divided according to the degree of accuracy. Different degrees of accuracy correspond to different basic error limits (expressed as a percentage of full-scale output). In practical applications, the selection is based on the control requirements of the measurement error and in accordance with the principle of economic use.

6, confirm the working temperature range

The measured medium temperature should be within the working temperature range of the transmitter. If it is used over temperature, it will produce a large measurement error and affect the service life. During the production process of the pressure transmitter, the temperature influence will be measured and compensated. The measurement error to ensure that the product is affected by temperature is within the range required by the accuracy level. In the case of high temperature, you can consider the choice of high temperature pressure transmitter or auxiliary cooling measures such as installing condenser tubes and radiators.

7. Confirm the compatibility of the measured medium and the contact material.

In some measurement occasions, the measuring medium is corrosive. In this case, materials compatible with the measuring medium or special processing must be selected to ensure that the transmitter is not damaged.

8, confirm the pressure interface form

In the company's products with threaded connection (M20 × 1.5) as the scale interface form, if customers need other special interface forms, can be designed and produced according to customer requirements.

9, confirm the power supply and output signal

The company's products use DC power supply, providing a variety of output signal options, including 4 ~ 20mA, 0 ~ 5VDC, 1 ~ 5VDC, 0 ~ 10mA and 232 or 485 digital output.

10. Confirm the working environment of the site and other

It is necessary to know whether there is vibration or electromagnetic interference, etc., and provide relevant information when selecting the type for the corresponding treatment. When selecting the type, other electrical connections, etc., can also be considered depending on the situation.

2. Note on product installation and use:

1. Read the product copy carefully before installation, accurately wire, and pay attention to the product wiring error.

2, the transmitter should be installed in the wind, dry, no corrosion, cool and small temperature changes. If it is installed in the open air, it should be equipped with a protective cover to avoid direct sunlight and rain to avoid product malfunction or malfunction.

3. It is strictly forbidden to randomly hit, impact, disassemble, strongly clamp or use a sharp tool to press the pressure hole or metal diaphragm.

4. Pay attention to the protective product lead-out cable. The cable joint should be sealed to prevent the water or moisture from affecting the function and life of the whole machine. After the transmission, the terminal lead should be well connected to the atmosphere.

5. When installing, load the pressure shut-off valve between the transmitter and the medium to check and prevent the pressure port from being blocked and affect the measurement accuracy. In the case of large pressure fluctuation range, a pressure buffer device should be installed.

6. When measuring steam or other high temperature media, be careful not to over-limit the operating temperature of the transmitter. If necessary, connect the pressure tube or other cooling device.

7. When measuring the liquid medium, the air in the pipeline must be drained by the shut-off valve before pressurization to prevent the high-pressure conduction sensor generated by the compressed air from being overloaded.

8. It is forbidden to overload the super-index, and the sensitive membrane damage caused by the overload of the super-index is not in the scope of the three-pack.

9. When the explosion-proof transmitter is used in a dangerous place, the cover of the transmitter must be tightened. To ensure the safety of use, the safety regulations should be strictly observed. It is absolutely not allowed to open the cover of the transmitter when the power is on.

10. Intrinsically safe transmitters must be equipped with a safety barrier to be used in hazardous locations with explosive mixtures. The safety barrier shall comply with the provisions of GB3836.4-2000 "Intrinsic Safety Types of the 4th Department of Electrical Equipment for Explosive Gas Environments", and shall be subjected to explosion-proof tests and obtain an explosion-proof certificate.