The static characteristics of the pressure sensor refer to the relationship between the output of the sensor and the input of the static input signal. Because the input and output are independent of time at this time, the relationship between them, that is, the static characteristics of the sensor can be described by an algebraic equation without time variables, or a characteristic curve drawn with the input as the horizontal coordinate and the corresponding output as the vertical coordinate. The main parameters characterizing the static characteristics of the sensor are linearity, sensitivity, hysteresis, repeatability, drift, load, long-term stability, measuring medium temperature, return error, etc.

(1) Linearity: refers to the degree to which the actual relationship curve between the sensor output and input deviates from the fitted straight line. Defined as the ratio of the deviation value between the actual characteristic curve and the fitted line in the full scale range to the full scale output value.

(2) Sensitivity: Sensitivity is an important indicator of the static characteristics of the pressure sensor. It is defined as the ratio of the increment of the output quantity to the corresponding increment of the input quantity that causes the increment. The sensitivity is denoted by S.

(3) Hysteresis: The phenomenon that the input and output characteristic curves of the sensor do not coincide during the change of the input amount from small to large (positive stroke) and the input amount from large to small (reverse stroke) becomes hysteresis. For the same size of the input signal, the positive and negative stroke output signal of the sensor is not equal, and this difference is called the hysteresis value.

(4) Repeatability: Repeatability refers to the degree of inconsistency of the characteristic curve obtained when the input quantity of the sensor is continuously changed in the full range in the same direction.

(5) Drift: The drift of the sensor means that the output of the sensor changes with time when the input is unchanged, which is called drift. There are two reasons for the drift: one is the structural parameters of the sensor itself; The second is the surrounding environment (such as temperature, humidity, etc.).