SIE Sensorik Industrie-Elektronik GmbH, Allgemeine Beschreibung

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A distinction is drawn between two different application categories for capacitive sensors:

1. S I E designation: Proximity Sensor (sensor version flush-mounted)
Sensors with a rectilinear electrical field. These devices scan solids (e.g. wafers, components, PCBs, hybrids, cartons, stacks of paper, bottles, plastic blocks and sheets) from a distance or liquids through a partition wall (glass or plastic, thickness max. 4 mm), and should in each individual case be tested beforehand with samples. See also the section on adjustment.

Fig. 1.03

2. S I E designation: Level Sensor (sensor version non-flush mounted)
Sensors with a spherical electrical field. These units are designed to detect the product, bulk goods or liquids (e.g. granulate, sugar, flour, corn, sand, or oil and water) with their active surface, by touching the medium or through tank wall.
The choice of the appropriate sensor depends on the operating conditions and the kind of medium and should in each case be tested beforehand with samples. See also the section on adjustment.

Fig. 1.04

Sensing distance S
This is the distance between the active sensor surface and the product being scanned at the moment of output-signal change as the object is approached.
It depends on shape, size and nature of the object concerned.

Fig. 1.05

Hysteresis
Hysteresis is the distance differential between the switch-on point (as the object approaches) and the switch-off point (as the object recedes again).

Repeatability
is the maximum sensing distance differential between any two measurements, measured within 8 hours with multiple „approaches“ to the object being scanned .

Material correction factor
If the material of the object concerned is not a metal or water, the sensing distance S will be reduced. Table 1.06 provides a guide to the reduction factors applying for the different materials involved. The precise values must be individually determined with the sensor actually being used.

Fig. 1.06

Sensing distance range or detection range (Sd)
is the range in which the sensing distance can be adjusted.

Effective sensing distance (Sr)
is the sensing distance measured for a sensor aimed at an earthed metal plate in accordance with IEC 60947-5-2.
It is sized so as to ensure that the edge length (m) of the square metal plate equals the sensor’s diameter or corresponds to three times the nominal sensing distance Sr, whichever is greater.
If the plate is made from a different material, is of smaller dimensions, not earthed or features a different shape or different characteristics, this will entail shorter sensing distances.

Installation: flush-mounted

Fig. 1.07

For flush-mountable sensors in plastic housings, the sensing distance must be adjusted after installation.

Installation: non-flush-mounted

Fig. 1.08

Installation: opposite
applies for flush and non-flush-mountable sensors.

Important!
The clearance for non-flush-mountable sensors (Fig. 1.08) must be complied with.

Fig. 1.09

Mounting torques
To ensure that the sensors are not mechanically destroyed during installation, make sure that you comply with the following torque figures.

Housing made of metal, approx.:

M5x0,5 / V2A	3 Nm
8x1 / V2A	15 Nm
M12x1 / V2A	40 Nm
M12x1 / MS	10 Nm
M18x1 / V2A	60 Nm
M18x1 / MS	25 Nm
M30x1,5/M32x1,5 / V2A	90 Nm
M30x1,5/M32x1,5 / MS	65 Nm

Housing materials
By choosing and combining the appropriate housing materials, sensors can be supplied for almost all environmental conditions.
PTFE is a special case among housing materials, by virtue of its outstanding resistance to chemicals. The S I E company offers a wide
choice of sensors entirely in PTFE (cPTFE).

The following housing materials are standard for capacitive sensors:

PVC	(= Polyvinyl chloride)
PTFE	(= Polytetrafluorethylene)
FEP	(= Tetrafluorethylene-Perfluorpropylene)
PUR	(= Polyurethane)
PBT/PET	(= Polybutylenterephtalate/Polyethylenterephtalate)
POM	(= Polyoxymethylene)
PA	(= Polyamide)
PSU	(= Polysulfone)
PC	(= Polycarbonate)
MS/Cr	(= Brass) chrome plated
Stahl/V2A	(= Stainless steel)

Laying the leads
The control leads to the sensors should be laid separately or shielded from the main power lines.

Please note!
The sensor lead for the SK mini-sensors with a 2-mm-Ø housing, M3, and a 10-mm-Ø / 2.5-high housing, must not exceed an overall length of max. 3 m.
The sensor lead for the SK mini-sensors from a housing Ø ³ 4 mm and a housing Ø ³ 18/4 high, must not exceed an overall length of max. 10 m.

EMC Directive and CE labelling
The sensors, sensor amplifiers and sensor secondary switchgear we produce comply with the statutory provisions of the European EMC Directive No. 89/336 EEC and thus with the Low-Voltage Directive No. 73/23 EEC.
The limit values stipulated in the Product Standard IEC 60947-5-2 are complied with.

In addition, we also supply sensors that meet the EMC specification laid down in the German Basic Standard for Industrial Applications.

Voltage drop U_d
The voltage drop is the voltage measured across the active output of the proximity switch when carrying the operational current flows under specified conditions.

Core identification
The individual cores of the sensor cables are colour-coded.

DC-units:
brown (br/bn) = +
blue (bl/bu) = -
black (sw/bk) = output

AC-units:
black (sw/bk) or brown (br/bn) = L1
blue (bl/bu) = N
green/yellow (gr/ge, gn/ye) = earth

IP degree of protection
The degrees of protection IP 20, IP 40, IP 54, IP 64 up to IP 68 are in accordance with IEC 60529.

Code letters IP (International Protection) designate protection against shock hazard, ingress of solid foreign bodies, and water, for electrical equipment
.

1^st digit:

2	protection against penetration of solid foreign bodies larger than 12 mm shielding from fingers or similar objects.
4	protection against penetration of solid, bodies larger than 1 mm, shielding from tools or wires.
5	protection against harmful dust deposits, complete shock-hazard protection.
6	protection against penetration of dust, complete shock-hazard protection.

2^nd digit:

no special protection.

protection against water spraying from all directions against the piece of equipment concerned.

protection against a water jet from a nozzle, directed from all directions against the piece of equipment concerned.

protection against water, when the piece of equipment concerned (housing) is immersed in water under specified pressure and time conditions.

Protection against water during continuous submersion.


IPx4..x6	IPx7..x8

Housings for a multitude of applications are labelled with the appropriate code number for jet-water and submersion.

Switching frequency
The switching frequency is a succession of periodically repeated activation and de-activation of the sensors during one second. Measuring method in conformity with IEC 60947-5-2.

Fig. 1.10

Standby current
This is the current the sensor consumes at maximum supply voltage without a connected load.

Operating voltage (U_B) or supply voltage
is the voltage range in which flawless functioning of the sensor is assured. It subsumes all voltage tolerances and residual ripples.

Operating current (I_e) or output current
is the maximum current with which the sensor may be loaded at its output in continuous operation.

Smallest operating current (I_m)
the minimum current that has to flow through the load in order to assure flawless functioning of the switching output stage. Stated for 2-wire AC/DC or AC devices.

Residual current (I_r)
is the current that can flow in the load circuit in the blocked state of the switching output stage.

Residual ripple
This is the maximum permissible AC voltage which may be superimposed on the supply voltage without affecting the function of the sensor.

Short-circuit protection and overload protection
The sensors normally contain this protective feature. In the event of overload or short-circuit at the output, the output transistor is automatically switched off. As soon as the malfunction has been corrected, the output stage is reset to normal functioning.

Polarity reversal protection
The sensor electronics are protected against possible polarity reversal or interchanging of the connection wires.

Ambient temperature
specifies the temperature range at which the sensor may be operated.
S I E SENSORIK manufactures both sensors for the standard temperature range of -30 … +70°C and sensors for more stringent temperature requirements up to max. +250°C.