|
|
An inductive proximity switch is designed to detect, and react to any metal object which moves into the operating zone situated immediately in front of its sensing face.
This sensing face comprises a coil, the winding of which is fed from
an oscillator, the whole creating an alternating magnetic field in front
of the coil.
Whenever a metal object moves into this field, the resulting induced currents form an additional load, and the oscillations cease.
Sensing Distance : The distance between the target and the active face at which the sensor switches.
Nominal Sensing Distance (Sn) : The operating distance for which the switch is designed. This value should only be taken as a guide, since no manufacturing tolerances, or changes in voltage or temperature, etc., during operation are taken into account.
Usable Sensing Distance (S) : The true sensing distance, derived by testing with a standard metal target during extremes of supply and temperature variations. Usually found as 0.80 Sn < S < 1.20 Sn.
Operating Sensing Distances : Is the distance at which a proximity sensor senses the target reliably. It is between 0 % and 80 % of the nominal sensing range.
Operating Voltage :
Voltage range in which the proximity sensor can function reliably.
Ripple : Ripple is the alternating voltage superimposed on the DC voltage (Peak - Peak) in %. For the operation of DC voltage switches, a filtered DC voltage with a ripple of 10 % maximum is required.
Voltage Drop : The maximum voltage drop across a conducting sensor.
No-Load Current : Is the consumption of current of a sensor in its non-active state.
Maximum Load Current : Is the maximum current which may be drawn continuously through the sensor in active state. Usually it is less than or equal to 60 % for reliable working of the sensor.
Normally Open Output (N/O) : This type of output will switch on the load whenever a target comes within the operating zone. (Normal condition is when no target is present).
Normally Closed Output (N/C) : This type of output will switch off the load whenever a target comes within the operating zone. (Normal Condition is when no target is present).
Changeover Output (N/O + N/C) : This type of output will switch two separate loads whenever a target comes within the operating zone. 1 Load will be switched on and the other will be switched off whenever a target comes within the operating zone. (Normal condition is when no target is present).
N. B. : DC switches employ a transistor as the output switching device. AC switches employ a thyristor as the output switching device.
NPN Output : Proximity sensor with NPN output switch the negative
potential to the load. It is also described as negative-switching or
current-sinking.
PNP Output : Proximity sensors with PNP output switch the positive
potential to the load. It is also described as positive-switching or
current-sourcing.
Repeatability : The repeat accuracy of a sensor to detect an object at the same distance from the active sensing face. It is expressed in mm or in percentage of the sensing distance.
Reverse Polarity Protection : Proximity sensors which are protected against reversal in voltage polarity.
Short Circuit Protection : Proximity sensor protected from damage when a shorted condition exists for an indefinite or defined period of time.
Switching Frequency : The maximum number of times per second the sensor can change its state (on and off) usually expressed in hertz (HZ).
Temperature Drift : Specification used to indicate the change in switching point caused by temperature variations within a specified ambient temperature range. Expressed as a percentage of the sensing distance.
Hysterisis : The difference between the operate (Switch-on) and
the release (Switch-off) is called hysterisis. This helps the sensor
to avoid chattering i.e. accidental switch cycling, when subject to
vibration, electrical noise, or temperature drift.
Standard Target : The active face of the proximity switch is the surface where a high-frequency Electro-Magnetic field emerges (However, no direct magnetic field occurs). The target consists of steel, 1 mm thick, square form with side lengths equal to the diameter of the sensing surface circle.
Target Correction Factors : To determine the sensing distance for materials other than the standard mild steel, a correction factor is used. Multiply the listed nominal sensing distance for that material. The correction factors listed below can be used as a general guideline.
| Mild Steel | Approx. 1.0 x Nominal Sensing Distance |
| Stainless Steel | Approx. 0.9 x Nominal Sensing Distance |
| Brass | Approx. 0.5 x Nominal Sensing Distance |
| Aluminium | Approx. 0.45 x Nominal Sensing Distance |
| Copper | Approx. 0.4 x Nominal Sensing Distance |
The size and shape of the target may also affect the sensing distance. The following should be used as a general guideline when correcting for the size and shape of a target :
Flush Installation : A proximity sensor can be mounted in metal upto the active surface. No side sensing occures in these sensors. However, the sensing distance is less in these sensors compared to non-flush sensors.
Non-Flush Installation : A proximity sensor must be installed
in such a way that metal free-zone is maintained (To avoid side sensing).
Sensors for non-flush mounting have an extended sensing distance compared
to sensors for flush mounting.
|
|
SPECIFICATIONS:
| Supply Voltage | 10 – 30 V DC |
| Ripple on Supply | 10% max. |
| No load Current | Less than 10 mA |
| Maximum load Current | 300 mA |
| Hysterisis | 15% max. |
| Operating Temperature | - 25oC to + 70oC |
| Output Transistor | PNP or NPN |
| Output Logic | No or NC or NO + NC |
| Environmental Protection | IP67 |
| Repeat Accuracy | Less than 0.02 mm |
| Temperature Drift | 5 % typical |
| Switch – ON effect Suppression | Incorporated |
| Reverse Polarity Protection | Provided |
| Short circuit Protection | Provided (For M 18 & above) |
| Status Indication | Provided thro’ LED |
SWITCHING FREQUENCY
| ø (mm) |
8 |
12 |
18 |
30 |
36 |
50 |
|
Hz |
2000 |
1000 |
800 |
300 |
200 |
100 |
FLUSH
MOUNTING
|
ø1 |
L 1 |
L 2 |
L |
Sn |
a |
ø1 |
L 1 |
L 2 |
L |
Sn |
|
8 |
45 |
-- |
45 |
1 |
a |
30 |
50 |
20 |
70 |
10 |
|
12 |
55 |
20 |
75 |
2 |
a |
36 |
35 |
20 |
55 |
15 |
|
16 |
55 |
20 |
75 |
5 |
a |
50 |
40 |
20 |
60 |
20 |
|
18 |
55 |
20 |
75 |
5 |
a | a | a | a | a | a |
|
20 |
50 |
20 |
70 |
5 |
a | a | a | a | a | a |
|
25 |
50 |
20 |
70 |
8 |
a | a | a | a | a | a |
NON FLUSH MOUNTING
|
ø 1 |
ø 2 |
L 1 |
L 2 |
L 3 |
L |
Sn |
ø 1 |
ø 2 |
L 1 |
L 2 |
L 3 |
L |
Sn |
|
12 |
10 |
45 |
20 |
5 |
70 |
4 |
36 |
33 |
35 |
20 |
25 |
80 |
20 |
|
18 |
16 |
45 |
20 |
10 |
75 |
8 |
50 |
46 |
40 |
20 |
20 |
80 |
25 |
|
20 |
16 |
50 |
20 |
10 |
80 |
8 |
a | a | a | a | a | a | a |
|
22 |
16 |
50 |
20 |
10 |
80 |
8 |
a | a | a | a | a | a | a |
|
25 |
23 |
50 |
20 |
10 |
80 |
10 |
a | a | a | a | a | a | a |
|
30 |
28 |
35 |
20 |
15 |
70 |
15 |
a | a | a | a | a | a | a |
Flush Mounting
Non Flush Mounting
|
|
| These Sensors are designed to work as solid state DC limit switches. The Sensors are connected directly in series with the load and have a bridge rectifier so they are not polarity conscious. The circuit design is such that, when in off state, it allows very small current to flow through the load. However, the output load (such as relay) should be chosen, considering the voltage drop across the switch in the ON State. These sensors find wide application in electric control circuits and PLC’s. |
SPECIFICATIONS:
| Supply Voltage (nominal) | 10 – 60 V DC |
| Voltage Drop across the Switch | Less than 6.8V |
| Maximum Load Current (Continuous) | 100 mA |
| OFF state Current | Less than 1 mA |
| Operating Temperature | - 25oC to +70oC |
| Hysterisis | 15 % max. |
| Switching Frequency | 5 Hz typical |
| Output Logic | NO or NC |
| Environmental Protection | IP 67 |
| Status Indication | Through LED |
|
FLUSH |
NON FLUSH |
||||||||||
|
ø 1 |
L 1 |
L 2 |
L |
Sn |
ø 1 |
ø 2 |
L 1 |
L 2 |
L 3 |
L 0 |
Sn |
|
18 |
55 |
20 |
75 |
5 |
18 |
16 |
45 |
20 |
10 |
75 |
8 |
|
25 |
50 |
20 |
70 |
8 |
25 |
23 |
50 |
20 |
10 |
80 |
10 |
|
30 |
50 |
20 |
70 |
10 |
30 |
28 |
35 |
20 |
15 |
70 |
15 |
|
36 |
35 |
20 |
55 |
15 |
36 |
33 |
35 |
20 |
25 |
80 |
20 |
|
50 |
40 |
20 |
60 |
20 |
50 |
46 |
40 |
20 |
20 |
80 |
25 |
|
|
| These Sensors are designed to provide better alternative to conventional limit Switches / micro switches. These are epoxy potted similar to other types of sensors to render IP67 protection and hence are suitable even in underwater applications. The load (Contactor / A.C. relay / Solenoid coil) is to be connected in series with the switch. |
SPECIFICATIONS:
| Supply Voltage (nominal) | 24 – 250 V AC |
| Supply Frequency | 45 – 65 Hz |
| Load Current | 500 mA max. |
| Leakage Current | 2.3 mA typical |
| Voltage Drop Across the Switch | 6.8 V |
| Maximum Inrush Current | 6A; t < 10ms; f < 5 |
| Minimum Load Current | 5 mA |
| Hysterisis | 10 % typical |
| Repeatability | 1 % typical |
| Temperature Drift | 5 % typical |
| Switch on effect Suppression | Provided |
| Output Logic | NO or NC or NO+NC |
| Status Indication | Through LED |
|
|
|
|
FLUSH |
NON FLUSH |
||||||||||
|
ø 1 |
L 1 |
L 2 |
L |
Sn |
ø 1 |
ø 2 |
L 1 |
L 2 |
L 3 |
L 0 |
Sn |
|
12 |
55 |
20 |
75 |
2 |
12 |
10 |
45 |
20 |
5 |
70 |
4 |
|
18 |
55 |
20 |
75 |
5 |
18 |
16 |
45 |
20 |
10 |
75 |
8 |
|
25 |
50 |
20 |
70 |
8 |
25 |
23 |
50 |
20 |
10 |
80 |
10 |
|
30 |
50 |
20 |
70 |
10 |
30 |
28 |
35 |
20 |
15 |
70 |
15 |
|
36 |
35 |
20 |
55 |
15 |
36 |
33 |
35 |
20 |
25 |
80 |
20 |
|
50 |
40 |
20 |
60 |
20 |
50 |
46 |
40 |
20 |
20 |
80 |
25 |
Flush Mounting
Non Flush Mounting
|
|
 |
|
| These are DC type proximity sensors and the technical specifications are similar to that of standard DC type Inductive Proximity Sensors. These find application in CNC / NC machines or where space is the constraint. These are available in ABS plastic enclosures. |
 |
|
| These are available only in DC type and the specifications of these Sensors match with our standard DC type Inductive Proximity Sensors. There are two models available – Flush and Non Flush mounting, housed in moulded ABS Plastic enclosures. |
 |
|
| These are called as slot sensors or fork sensors and are available in DC (3 wire version). AC (2 wire version) and DC (2 wire version); Sensors with different sensing gap also can be manufactured on request. |
 |
|
| These are T type switches and are provided with oil ring. These are available in DC (3 wire) & AC (2 wire) versions with sensing distance as high as 4 mm. The sensors are housed in moulded ABS plastic enclosures. |
 |
|
| These are called as block type proximity sensors and are available in DC (3 wire / 4 wire), DC (2 wire) and AC (2 wire) version. The sensing zone can be kept on any face of the sensor, making them front sensing, side sensing, Top sensing or Bottom sensing sensor. |
 |
|
| These are pentagonal proximity sensors and considered as better alternative to conventional limit switches. These are stackable type and the sensing distance can be as high as 5 mm. These are housed in cast aluminium enclosures. |
|
|
| Inductive
Proximity Sensor can be used :
# To drive DC relay # To drive DC contactor (ask for load current 500 mA) # To drive AC relay / AC contactor # Can be coupled directly to any PLC / Logic Circuit #
Can be used as an input for a Digital Counter / RPM
|
Introduction
| Infrastructure | Quality
control | Proximon Products
Dealers network | Contact
Us | Project Division
ABB Drives | ABB
PLC | Hengstler Encoder | Hengstler
Counter | Application Area
Comments: proximon@vsnl.com
Copyright
© 2000 Proximon
Controls Pvt. Ltd.