# The Common Terms Used in the Model Selection of Low Differential Pressure Sensor

The pressure is one of the important parameters in industrial production. To ensure the normal operation of production, pressure must be monitored and controlled. The following are the terms commonly used in the model selection of the low differential pressure sensor:

1. Standard pressure

It refers to the magnitude expressed by taking the atmospheric pressure as the standard, the pressure greater than the atmospheric pressure is called positive pressure, while the pressure less than the atmospheric pressure is called negative pressure.

2. Absolute pressure

It refers to the magnitude of pressure expressed by taking the absolute vacuum as the standard.

3. Relative pressure

The magnitude of the pressure for the comparison object (standard pressure).

4. Atmospheric pressure

It refers to the atmospheric pressure. The standard atmospheric pressure (1atm) is equivalent to the pressure of a mercury column with a height of 760mm.

5. Vacuum

It refers to the pressure state below atmospheric pressure. 1Torr=1/760 atmospheric pressure (atm).

6. Detection pressure range

It refers to the adaptive pressure range of the low differential pressure sensor.

7. The pressure that can withstand

When the low differential pressure sensor returns to the detection pressure, its performance does not degrade under the pressure that can withstand.

8. Round-trip precision

At a certain temperature (23°C), when the pressure is increased or decreased, the pressure variation value at the operating point is obtained by dividing the pressure value of output reversal with the full-scale value of the detection pressure.

9. Precision

At a certain temperature (23°C), when zero pressure and rated pressure are applied, the value is obtained by dividing the deviation from the specified value of the output current (4mA, 20mA) with the full-scale value, the unit is expressed by %FS.

10. Linearity

The output of the simulated low differential pressure sensor varies linearly with the detection pressure, but it has a deviation compared with the ideal straight line. The value of this deviation expressed as a percentage of the full-scale value is called linearity.

11. Hysteresis

Use zero voltage and rated voltage to draw an ideal straight line between the output current (or voltage) value, find the difference between the current (or voltage) value and the ideal current (or voltage) value as the error, and then find the error value when the pressure rises and when it falls. The value obtained by dividing the maximum value of the absolute value of the above difference with the full-scale current (or voltage) value is the hysteresis. The unit is expressed by %FS.