Pressure transmitter
Description
I. Product overview
The pressure transmitter is used to measure the liquid level, density and pressure of the liquid, gas or steam, which is then converted into 4 ~ 20mA DC signal output. The pressure transmitter can communicate with HART manual operator, through which setting, monitoring or with the host unit into a field monitoring system.
Two, the working principle
Pressure transmitter process pressure is transferred to the central measuring diaphragm in chamber d through the isolation diaphragm on either side or the filling fluid on one side. The central diaphragm is a tensioning elastic element, which produces corresponding deformation displacement for the pressure difference between the two sides acting on it, and its displacement is proportional to the differential pressure. The large displacement of z.u is about 0.1mm. This displacement is transformed into a differential capacitor on the capacitor plate, and the differential capacitor is converted into a two-wire DC signal output of 4~20mA by the electronic circuit.
Three, installation skills
The installation position of the pressure transmitter on the process pipeline is related to the medium under test. The following conditions should be taken into account during installation:
1, as far as possible to avoid the transmitter and corrosive or overheated medium under test direct contact.
2, to prevent sediment in the pressure guide tube.
3. The pressure guide tube should be as short as possible.
4. The liquid column pressure in the pressure guide tube on both sides should be balanced.
5. The pressure guide pipe should be installed in the place where the temperature gradient and temperature fluctuation are small. When measuring liquid flow, the pressure port should be opened on the side of the flow line to avoid sediment. At the same time, the transmitter should be installed next to or below the pressure port so that the bubbles can be discharged into the process pipe. When measuring gas flow, the pressure port should be opened at the top or side of the flow pipe. And the transmitter should be installed next to or above the process pipe so that the accumulated liquid can easily flow into the process pipe. Four, the price of the product pressure transmitter price is related to the model, the price of different models is not the same, such as 2088 diffusion silicon pressure transmitter, compact pressure transmitter, high temperature pressure transmitter, their price is not equal, z.u final offer should be based on the site condition, model.
V. Product parameters
Measuring medium | Gas, liquid, oil and other media compatible with 316 |
Form and scope of measurement | Gauge pressure (G) Z.i is high (0 ~ 60)MPa, Z.i is low (0 ~ 0.5)KPa |
The absolute pressure (A) is as high as (0 ~ 40)MPa and as low as (0 ~ 5)KPa | |
Negative pressure (B) (-0.1 ~ 40)MPa, z.u small (-0.2 ~ 0.2)KPa | |
Precision class | 0.1、 0.25、 0.5 |
Overload capacity | 2 ~ 5 times the range |
Long-term stability | Less than 0.25%FS/ year, less than 0.5%FS/ year |
Power supply | 15 ~ 36 VDC (calibration voltage 24VDC) |
Output message | (4 ~20)mA (two/three wire system), (0~ 10) MA (0~20)mA (0 ~ 5) V, (1 ~ 5) V, (0 ~ 10) V |
Display mode | Pointer head or digital display is optional |
calibration | The zero and range can be adjusted by adjusting the precision potentiometer Operating temperature: (-40 ~ 80) ℃ Compensation temperature: (-20 ~ 70) ℃ |
Operating temperature | -40 ~ 80℃ compensation temperature: -20 ~ 70 ℃ |
Process connection | M20×1.5 external thread (with diameter of 3 inner holes) or user's indication |
Isolation diaphragm material | 316 stainless steel |
Sensor interface material | 1Cr18Ni9Ti |
Shell material | Alloyed aluminum |
Protection class | IP65 |
Vi. Model classification
Pressure transmitter classification | Pressure measuring range | Service temperature | Medium temperature | Application situation | |||||
2088 Pressure transmitter | -0.1 to 60MPa | -40 ~ 80 ℃ | -40 ~ 330 ℃ | Harsh environment | |||||
Sanitary pressure transmitter | 0~100KPa~35MPa | -40 ~ 80 ℃ | -40 ~ 300 ℃ | Wine, fruit juice food medium | |||||
High temperature pressure transmitter | -0.1 to 60MPa | -40 ~ 80 ℃ | -40 ~ 300 ℃ | Heat conduction oil, high temperature gas | |||||
Digital pressure transmitter | -0.1 to 60MPa | -40 ~ 80 ℃ | -40 ~ 300 ℃ | Steam, hot gas | |||||
Note: Different manufacturers of media, temperature, working conditions, its selection is not the same, the function is also different, selection examples: medium liquor, temperature 100 ℃, range 0~500KPa, wine belongs to the food industry, you can choose hygienic pressure transmitter.
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