Permanent or electric magnetic fields are influencing especially inductive or magnetic sensors. Through suitable constructive and electronic measures inside the sensor, this influence can be suppressed almost completely.
The plausibility test done by the microprocessor and the permanent averaging provide a higher interference immunity and guarantee the stability of the measuring results because of the fact that multiple echos are evaluated. The switching speed of the sensor depends on the chosen noise blanking. In this way, all sudden changes (for example agitators) are hidden when there is an optimisation on axiale approximation. Applications with lateral approximation of the measuring object, demand a very fast reaction of the sensor to dramatical changes. Because of this, the noise blanking can be programmed and adapted to the individual demands.
All given switching distances refer to a grounded measuring metal tag of ST 37 with 1 mm thickness. The length of the edges matches the sensor's diameter or the triple nominal switching distance if this value exceeds the sensor's diameter.
To maintain the conductivity of the switching element in position ON, all devices need a minimum operating current.
Modulated light means that each time, the light transmitter is only switched on shortly and switched off during a longer break (clock ratio ca. 1:25). The receiver is only active during the light pulse (valid for reflective light barriers and retro-reflective sensors) but locked during the break. By the use of modulated light, you receive the following advantages: - Largely insensitive against extraneous light - Higher detection area - Lower heating and therefore longer lifetime of the transmitter diodes
Optical sensors are working with alternating light to assure that they are largely insensitive against extraneous light. The modulation frequency fcy amounts several kHz. If a device is used within the radiation range of another one that has the same modulation frequency, there can occur disruptive effects. If the problem cannot be solved by aligning the devices or the help of apertures, we can optionally supply devices with different modulation frequencies.
Within a functional group of sensors, the devices are working with almost similar alternating fields or wave lengths. In doing so, the sensors are influencing theirselves mutually when they are mounted directly side-by-side or faced to each other. To avoid this, the assembly should be realised in regard to their construction requirement or by the use of devices with special tuned separated frequencies or wave lengths.