Switching Distance

Inductive Sensors

Operating Distance (Sensing Range) Considerations

The operating distance (S) of the different models is basically a function of the diameter of the sensing coil. Maximum operating distance is achieved with the use of a standard or larger target. Rated operating distance (Sn) for each model is shown. When using a proximity sensor the target should be within the assured range (Sa).

Operating Distance = S
The operating distance is the distance at which the target approaching the sensing face along the reference axis causes the output signal to change.

Standard Target
A square piece of mild steel having a thickness of 1 mm (0.04 in) is used as a standard target to determine the following
operating tolerances. The length and width of the square is equal to either the diameter of the circle inscribed on the active
surface of the sensing face or three times the rated operating distance Sn, whichever is greater.

Rated Operating Distance = Sn
The rated operating distance is a conventional quantity used to designate the nominal operating distance. It does not take
into account either manufacturing tolerances or variations due to external conditions such as voltage and temperature.

Effective Operating Distance = Sr 0.9 Sn ≤ Sr ≤ 1.1Sn
The effective operating distance is the operating distance of an individual proximity sensor at a constant rated voltage and
23°C (73°F). It allows for manufacturing tolerances.

Usable Operating Distance = Su 0.81 Sn ≤ Su ≤ 1.21Sn
The usable operating distance is the operating distance of an individual proximity sensor measured over the operating
temperature range at 85% to 110% of its rated voltage. It allows for external conditions and for manufacturing tolerances.

Assured Operating Range = Sa 0 ≤ Sa ≤ 0.81Sn
The assured actuating range is between 0 and 81% of the rated operating distance. It is the range within which the correct
operation of the proximity sensor under specified voltage and temperature ranges is assured.