MPA / MPS-T / MPS-C ..uneven Analogue Output

Hi everybody,

Every now and then we got some requests concerning an unstable or uneven output on our analogue magnetic sensors.

Most of the time they send us a graph from an oscilloscope which looks for example like this:

So what does this mean??

First of all some facts concerning our analogue magnetic cylinder sensors:

• Magnetic sensors are “passive”, the behavior of them is always depending on the magnet. 
• The Algorithm inside of the measurement system will react to the existing magnetic field AND (more importantly) will react and adjust the sensor if the magnetic field strength changes.

So what we see here in the output graph is only a reaction to changing magnetic field. So what happens usually? It is recommend to move the magnet 1 or 2 times over the whole range. Our sensor will adapt to the magnetic field strength and that´s it. But now it could happen that you have for example vibration or heat in close to the sensor. This could lead to a change of strength from magnetic field. The sensor will react to it and leave the output signal as it was until the new level is adapted in the sensor.

Most of the time this behavior happens if the magnet is not 100% parallel to the sensor. Even tiny changes in the distance could lead to that behavior.