Offset, scope, calibration and temperature compensation can be realized through the thin film resistor network, this kind of thin film resistor network in the process of encapsulation with laser correction.

The sensor is usually combined with micro controller, and micro controller embedded software itself sensor mathematical model is established. Microcontroller reads the output voltage, through the transformation of adc, the model can converts voltage stress measurements.

The mathematical model of sensor is the most simple is the transfer function. The model can be in the entire calibration process is optimized, and the maturity of the model will increase with the increase of the asm.

From the perspective of metrology and measurement error is quite strict definition: it is characterized by measuring the pressure and the difference between the actual pressure. Often unable to get the actual pressure directly, but can through the adoption of the standard to estimate the appropriate pressure, metrologists usually adopt the accuracy of at least 10 times higher than the device under test standard as measuring instrument.

Because without calibration system can only use the typical sensitivity and offset value converts the output voltage to pressure, measured the pressure will be error.

The initial error without calibration consists of the following parts:

A. the offset error. Due to the constant vertical migration in the whole pressure range, so the converter diffusion and amendments to the laser control changes will produce offset error.

B. error sensitivity, produce the error size is proportional to the pressure. If the device sensitivity is higher than the typical values, error sensitivity will be pressure increasing function (see figure 1). If the sensitivity is lower than the typical values, error sensitivity will be pressure decreasing function. The error reason lies in the diffusion process of change.

C. linear error. This is a small effect on initial error factors, the causes of the error is physical nonlinear of silicon, but for sensor band amplifier, should also include the nonlinear amplifier. Linear error curve can be concave curve, can also be a convex curve.

D. lag error: in most cases, completely negligible hysteresis error, because silicon has high mechanical stiffness. Generally only in case of pressure change a lot considering lag error.

Calibration can eliminate or greatly reduce these errors, and compensation technology usually requirements determine the parameters of system transfer function is actual, rather than simply using typical values. Potentiometer, adjustable resistance, and other hardware can be used in the process of compensation, while the software can work more flexibly to realize the error compensation.