Proximity Sensors Technical Guide
●
Design
Sensing Object Material
The sensing distance varies greatly depending on the material of the
sensing object. Study the engineering data for the influence of
sensing object material and size and select a distance with sufficient
leeway.
•
In general, if the
sensing object is a non-
magnetic metal (for
example, aluminum),
the sensing distance
decreases.
Size of Sensing Object
In general, if the object is smaller
than the standard sensing
object, the sensing distance
decreases.
•
Design the setup for an object
size that is the same or greater
than the standard sensing
object size from the graphs
showing the sensing object
size and sensing distance.
•
When the size of the standard
sensing object is the same or
less than the size of the
standard sensing object,
select a sensing distance with
sufficient leeway.
Thickness of Sensing Object
•
The thickness of ferrous metals
(iron, nickel, etc.) must be 1 mm
or greater.
•
When the coating thickness is
0.01 mm or less, a sensing
distance equivalent to a
magnetic body can be obtained.
When the coating is extremely
thin and is not conductive, such
as a vacuum deposited film,
detection is not possible.
•
Influence of Plating If the
sensing object is plated, the
sensing distance will change
(see the table below).
Effect of Plating (Typical)
(Reference values: Percent of non-plated sensing distance)
Mutual Interference
•
Mutual interference refers to a state where a Sensor is affected by
magnetism (or static capacitance) from an adjacent Sensor and the
output is unstable.
•
One means of avoiding interference when mounting Proximity
Sensors close together is to alternate Sensors with different
frequencies. The model tables indicate whether different
frequencies are available. Please refer to the tables.
•
When Proximity Sensors with the same frequency are mounted
together in a line or face-to-face, they must be separated by a
minimum distance. For details, refer to
Mutual Interference
in the
Safety Precautions
for individual Sensors.
Power Reset Time
A Sensor is ready for detection within 100 ms after turning ON the
power. If the load and Sensor are connected to separate power
supplies, design the system so that the Sensor power turns ON first.
Aluminum
Copper
Brass
Stainless steel
Steel
(SPCC)
0
5 10 15 20 25 30 35 40 45 50 55
Side length (one side) of sensing object: d (mm)
14
12
10
8
6
4
2
X
d
t=1mm
Sens
ing d
istance X (mm)
Example: E2-X10D
@
Stability
Side length (one side)
of sensing object: d (mm)
Sens
ing d
istance X (mm)
Standard
sensing
object
Sensing
distance
becomes
short
Thickness and base material of
plating
Steel
Brass
No plating
100
100
Zn 5 to 15
μ
m
90 to 120
95 to 105
Cd 5 to 15
μ
m
100 to 110
95 to 105
Ag 5 to 15
μ
m
60 to 90
85 to 100
Cu 10 to 20
μ
m
70 to 95
95 to 105
Cu 5 to 15
μ
m
-
95 to 105
Cu (5 to 10
μ
m) + Ni (10 to 20
μ
m)
70 to 95
-
Cu (5 to 10
μ
m) + Ni (10
μ
m)
+ Cr (0.3
μ
m)
75 to 95
-
Aluminum
Steel
0 0.01
0.1
1
10
Thickness of sensing object: t (mm)
10
8
6
4
2
Sens
ing d
istance X (mm)
Reset
Operate
Sensing object shape: Square
d=30mm
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