Page 6 of catalogue Capacitive sensors of Rechner Industrie-Elektronik GmbH

ADJUSTMENT
Analog Capacitive sensors are equipped with a 20-turn spindle potentiometer. This allows adjustment of an application specific operating range between the minimum distance “0 mm” and the type-typical maximum value. Consequently, the full output current range (4...20 mA) is always present, regardless of the required measuring distance. The Analog Sensors of series 80 are designed with a 2-colour LED which facilitates adjustment. Outside the operating range IA < 4 mA and IA > 20 mA green light is emitted to display operational readiness. Within the operating range of 4...20 mA the LED is yellow. In the undamped state the output current value is > 20 mA and moves with the reduction of the object distance toward 4 mA (value at total damping approx. 2.5 mA). In the case of series 40 the current characteristic is reverse-proportional to the object-distance. The data of the nominal sensing distance are based on the measuring method according to DIN VDE 0660, Part 208. The respective nominal sensing distance is indicated with a tolerance of + 10 %. The standard measurement plate is square with a thickness of 1 mm and is made of carbon steel FE 360 (defined in ISO 630: 1980 ) with a smoothed surface and earthed. The side lengths are equal to the diameter of the active area of the KAS or equal to 3 x Sn, depending on which value is greater. With a different material or a smaller surface of the actuating element, the sensing distance is smaller

Adjustment of the sensing distance is made by means of a spindle potentiometer with the screwdriver provided. With pluggable Sensors > M18x1 / Ø 20 the potentiometer is on the side.

Typ. response-time characteristic

The possible sensing distance for a particular material is dependent on the dielectric permittivity εr and can be worked out by means of the typical reduction factors: Sensing distance = Sn x reduction factor.

Material: Reduction factor approx.

F E 360

S t 37

Water

Wheat

Wood

Glass

Oil

PVC

PE

Ceramic

1

1

1

0,8

0,7

0,6

0,4

0,4

0,37

0,3

6

RECHNER Industrie-Elektronik GmbH • Gaußstraße 8-10 • D-68623 Lampertheim • Tel. +49 (0) 62 06 50 07-0 • Fax +49 (0) 62 06 50 07-20 • email info@rechner-sensors.de • www.rechner-sensors.de

All specifications are subject to change without notice. (05/2004)

For size M30x1.5 / ∅ 30: First open plastic tab. For size > M30x1.5 / ∅ 30: First remove plastic sealing screw.