The causes of interferences and their effects on electronics and its environment are various.
In industrial environments, as in the case of a steelworks, extremely high loads are switched due to the inconceivably large masses to be moved and high currents flow. Therefore, the potential for the ground connection of individual sensors or actuators can change at short notice.
These potential differences, which meet at a common point, are known as ground loops. Ground loops can have different effects: from interference with the measuring signal in the form of peaks or noise, to destruction of the hardware itself, e.g. through overvoltage.
However, this example only illustrates one possible consequence which entails the use of non interference-free products. The cables of the device itself can also cause later interference. The topic of interference resistance begins with measurement and automation technology before the actual signal acquisition. Interference such as EMC radiation, switching contactors etc can have an effect directly on the cables between the signal source – the sensor – and the downstream connection equipment, e.g. clamping plates. Often, the interference originates from the laying of the cable: for example, a switching contactor directly next to the cable can cause interference. This interference is then visible in the signal and is also measured.
An additional potential interference factor is electromagnetic compatibility or EMC. During operation of electronic devices, there is also always a conversion of electromagnetic field energy into other energy forms, e.g. heat or mechanical energy. However, this is not strictly limited to the device, but can also radiate into the surrounding electronics. The functions of other electronic equipment are affected by this EMC radiation and the equipment can potentially be severely damaged.
The use of electronics in harsh environments poses additional risks: Dirt that circulates in the surroundings can contaminate the sensors. Blocked sensory devices, for example, invalidate the final measurement value. Severe temperature fluctuations also affect the smooth operation of the devices. If the surrounding temperature is outside the tolerance range for the electronics, these no longer function without errors. Vibrations, which are difficult to avoid in harsh environments, can cause noises in the signal acquisition. In addition, these vibrations can damage the solder connections.