1. Sensor noise and its reduction measures
Sensor noise refers to all unwanted signals that appear in the sensor in addition to the signal being measured. It can be generated internally by the sensor or mixed with the signal from the outside. In general, noise is an irregular change, periodic fluctuations such as single AC noise and noise in a broad sense.
The noise generated inside the sensor includes noise generated by sensitive components, conversion components and conversion circuit components, and noise generated by the power supply. For example, an optical vacuum tube radiates irregular electrons, noise generated by semiconductor carrier diffusion, and the like. Reducing the temperature of the component reduces thermal noise, and electrostatic shielding of the power transformer reduces AC ripple noise.
The humming sound that is mixed into the sensor from the outside can be classified into mechanical noise, acoustic noise, thermal noise (such as relative displacement or performance change of the component due to thermal radiation), electromagnetic noise, and chemical noise. For vibration and other mechanical noise, anti-vibration table can be used or the sensor can be fixed on a large mass base. The effective way to eliminate the acoustic noise is to surround or place the sensor in the vacuum container; eliminate electromagnetic noise. The effective way is to shield and ground or to keep the sensor away from the power line, or to shield the output line, twist the output line together, and so on.
Post time: May-31-2021