1. The gauge sub have bubbles or impurities
2. Strain gauge itself performance is not stable
3. The circuit of solder joints
4. The stress of the elastomer release is not completely; In addition, and magnetic field, frequency, temperature and so on many. Electric drift or some drift can exist, but we can through some ways to narrow the scope or correction.
Zero thermal drift of pressure sensor performance is an important index, a widely attention. International think zero thermal drift only depend on the force sensitive resistance unequal and its temperature is nonlinear, actually zero thermal drift is associated with the reverse leakage current of power resistor. In this regard, polysilicon can remove impurities of heavy metals in substrate absorption, so as to reduce the force sensitive resistance of reverse leakage and improve thermal drift of zero point, improve the performance of the sensor.
What way and narrow electric drift correction electric drift? Zero electric drift in addition to affect the measurement precision and reduce the sensitivity of pressure sensor, what important?
Using zero electric drift can eliminate the thermal drift of pressure sensor, the so-called zero drift, refers to when the amplifier input short circuit, be irregular and changes in the input voltage of slow phenomenon. Zero drift of the main reason is the influence of temperature change on the transistor parameters as well as the power supply voltage fluctuations, etc., in the majority of the amplifier, has the greatest effect in the former magnitude zero drift, series and the greater the magnification, the more the more serious the zero drift.
Drift mainly depends on the size of the strain, material selection of the structure or composition determines the stability of the material or heat sensitive.
Materials are chosen after processing is very important also, technology is different, can produce different effect of strain values, the key is through some aging after adjustment, the stability of the bridge value or regular changes.
Drift adjustment means a lot, mostly according to the conditions of the factory or production requirements, most of the manufacturers of zero drift control very well. Internal resistance temperature and heating temperature control by zero acuity compensation, aging resistance, etc.
For the circuit switching transformer, the circuit part of the drift can be used by choosing good components and design more appropriate circuit to compensate.
Strain material should choose high sensitivity coefficient, small temperature change of the material.