Difference between ferrous and non-ferrous products
- Ferrous products:Â any steel
- Non-ferrous products: any metal except steel (brass, copper, etc.)
Caution - non-ferrous does not mean any material (wood, plastic, etc.)
Difference between ferrous sensors and non-ferrous sensors
There are sensors which can detect:
Ferrous metals as a preference (steel, iron)
The sensing distances for these products vary according to the metals to be detected: maximum for ferrous and dependent on a Km coefficient typical of each metal (value between 0 and 1: Km = 1 for steel). This coefficient reduces the sensor detection range. For example if Km = 1 for cast iron, it is only 0.25 for copper. This is the conventional inductive sensor.
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Both for ferrous (steel, iron) and non-ferrous (brass, aluminium, copper, etc) metals
The sensing distance for these sensors is the same for both ferrous and non-ferrous materials. The Km coefficient is always 1. They are called Ferrous/Non-Ferrous sensors. The Schneider part numbers are: XS1M18KPM40x, XS1M30KPM40x 18mm and 30mm diameter sensors respectively, and also XS7C40KPM40.
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Difference in detection principlesÂ
For both sensors, an LC oscillator creates an electromagnetic signal.
The difference in detection principles for the two types of sensor lies in:
- Attenuation of the oscillation amplitude for ferrous materials, it is significant for ferrous materials and insignificant for non-ferrous materials
- Variation in oscillation frequency for ferrous/non-ferrous materials. For high-frequency operation (in the region of one MHz), both types of material (ferrous and non-ferrous) have the same effect on the oscillation frequency variation.
Km coefficient depending on the different metals