Pressure sensors generally have two-lined, three-lined, four-lined and, in some cases, five-lined。
The two-wire system of the pressure sensor is relatively simple, and the general customer knows how to connect, one line connects to the positive power pole, and the other, the signal line connects through the instrument to the negative of the power pole, which is the simplest, and the three-wire system of the pressure sensor is based on the two-wire system, which is directly connected to the negative pole of the power source, which is more problematic than the two-wire system。
The four-lined pressure sensor must have been two power input ends, the other two being the signal output end. Most of the four-lined output is voltage output rather than 4-20ma output, and the four-20ma is called pressure transmitter, most of which is made in two lines。
Some of the signal outputs of pressure sensors are not amplified, with a full range output of only a few dozen millivs, while some of the pressure sensors have an internal magnification circuit with a full range output of 0-2v。
As for how to get the display, it depends on the scale of the instrument, which can be measured directly if there are slots corresponding to the output signal, otherwise the signal adjusts the circuit. The five-line pressure sensors are not much different from the four-line sensor, and the market-based five-line sensors are relatively small。
Physical chart of pressure sensor attachment lines
Elements of pressure sensor installation
1. Open the monitor before connecting to the pressure sensor system。
2. Open packaging using disinfection measures to confirm that all interfaces are securely sealed and that supporting parts such as the three valves are in good working condition。
Note: when connecting, do not twist too tight。
3. All vents of the rotor valve shall have a holed protective hat until hepatophate water solubles and exhaust air bubbles are filled in the sensor system and replaced with an holesless protective cap。
4. Connect pressure sensors to the monitor, which is transferred to zero according to the instruction of the monitor。
Note:
1 if this is not possible, replace the sensor with zero; if this is not successful, check whether cable connections, monitors, etc. Are normal。
Unavoidable error of pressure sensors
1. Offset error
Since the pressure sensor is constant in vertical deviations throughout the pressure range, the variation of the transformer and changes in laser adjustments will result in a deviation error。
2. Sensitivity error
The amount of error generated is proportional to the pressure. If the device is more sensitive than typical values, the sensitivity error will be an incremental function of pressure. If sensitivity is below typical values, sensitivity error will be a diminishing function of pressure. This error is due to changes in the proliferation process。
3. Linear error
This is a factor that has a lesser impact on the initial error of the pressure sensor, which is due to the physical non-linear nature of the silicone, but for sensors with amplifiers, the non-linearity of the amplifier should also be included. A linear error curve can be either a conic or a conic。
4. Delay error
In most cases, the lag error of the pressure sensor is entirely negligible, as the silicon tablets have a high mechanical rigidity. It is generally only necessary to consider lag errors in situations of great stress。
