The use of non interference-free products can have serious effects. The effects vary and depend on the type of interference in question. When manufacturing metal sheets in a steelworks, for example, enormous loads are switched and there are high currents which can lead to a short-term change in the potential for the ground connection of individual sensors. These potential differences are known as ground loops. With non interference-free electronics, these ground loops can severely affect the measurement signal in the form of peaks or noise; a valid measurement signal is therefore no longer feasible. Very large potential differences result in large overvoltage. In extreme cases, these can even destroy the hardware or cause a complete failure of the control unit of the device. The cause in this case is a lack of optical isolation between the individual modules.
By using interference-free products, signal interference can be prevented when taking measurements. In the worst case, if very large potential differences occur, only the channel affected by the interference or the respective module will fail thanks to the optical isolation of up to 1,000 V. The failure of all control components is impossible.
In addition, all electronic devices which are not protected against high-frequency interference such as EMC radiation are helpless in the face of interference pulses. This interference can lead to measurements with errors, signal noise, or malfunctions in the device itself. In addition, external devices in the close surroundings can be negatively affected or even damaged by EMC radiation from a non interference-free product. Similar interference is caused by missing filters or by vibrations in the environment, which causes a noise when acquiring the signal. Vibrations are difficult to avoid in harsh environments. A lack of protection against damaging vibrations can lead to malfunctions or even the complete failure of the device in the worst-case scenario.
Not using interference-free products may cost less, but only at the risk of a host of negative consequences: from imprecise measurements to the complete failure of the control unit or the device itself.