Pressure transmitter
Description
I. Product Overview
Pressure transmitters are used to measure the level, density, and pressure of a liquid, gas, or vapor, and then convert to a 4 to 20mA DC signal output. The pressure transmitter can communicate with the HART operator, through which to set, monitor or with the upper unit into a field monitoring system.
Two, the working principle
Pressure in the process of pressure transmitter is transmitted to the central measuring diaphragm of chamber D through isolation diaphragm on both sides or one side and filling fluid. The central diaphragm is a tensional elastic element, which produces the corresponding deformation displacement for the pressure difference on both sides of it. The displacement is proportional to the differential pressure, and the displacement is about 0.1mm. The displacement is transformed into a differential capacitance on the capacitor plate, and the differential capacitance is converted into 4-20mA DC signal output by the electronic circuit.
Three, installation skills
The installation position of the pressure transmitter on the process pipe is related to the medium to be measured. The following should be considered during installation:
1, as far as possible to avoid transmitter and corrosive or overheated medium direct contact.
2, to prevent dross deposition in the pressure tube.
3, the pressure tube should be as short as possible.
4. The liquid column pressure in the pressure tube on both sides should be kept in balance.
5, the pressure guide tube should be installed in the temperature gradient and temperature fluctuation small place. When measuring liquid flow, the pressure outlet should be opened on the side of the flow pipe to avoid sediment deposition. At the same time, the transmitter should be installed next to or below the pressure inlet, so that the bubbles are discharged into the process pipe. When measuring gas flow, the pressure outlet 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. The price of pressure transmitter 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 the same, THE final quotation should be based on the field condition, model.
5. Product parameters
| Measuring the dielectric | Gas, liquid, oil and other compatible with 316 media |
| Measurement form and scope | Table pressure (G) z.II large (0 ~ 60)MPa, Z.II small (0 ~ 0.5)KPa |
| The absolute pressure (A) is greater than (0 ~ 40)MPa and smaller than (0 ~ 5)KPa | |
| Negative pressure (B) (-0.1 ~ 40)MPa, Z.uni small (-0.2 ~ 0.2)KPa | |
| Precision grade | 0.1、 0.25、 0.5 |
| Overload capacity | 2 ~ 5 times of 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) |
| The output | (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 or digital display is optional |
| The calibration | By adjusting the precision potentiometer to achieve zero and range adjustment Working temperature :(-40 ~ 80) ℃ compensation temperature :(-20 ~ 70) ℃ |
| Working temperature | -40 ~ 80℃ Compensation temperature: -20 ~ 70 ℃ |
| Process connection | M20×1.5 external thread (ф 3 inner hole) or specified by user |
| Isolation diaphragm material | 316 stainless steel |
| Sensor interface material | 1Cr18Ni9Ti |
| The shell material | Aluminum alloy |
| Protection grade | IP65 |
Six, type classification
| Pressure transmitter classification | Pressure range | The use of temperature | Medium temperature | applications | |||||
| 2088 pressure transmitter | 0.1 ~ 60 mpa | - 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 ~ 60 mpa | - 40 ~ 80 ℃ | - 40 ~ 300 ℃ | Heat conduction oil, high temperature gas | |||||
| Digital display pressure transmitter | 0.1 ~ 60 mpa | - 40 ~ 80 ℃ | - 40 ~ 300 ℃ | Steam, high temperature gas | |||||
Note: Different manufacturers of medium, temperature, working conditions, its selection is not the same, the function is not the same, selection example: medium liquor, temperature 100 ℃, range 0~500KPa, wine belongs to the food industry, can choose sanitary pressure transmitter.
