Rain/light sensors

Electrics and ElectronicsSensors & actuators

Comfortable and reliable: HELLA rain-light sensors (RLS) have already been impressing with their quality and functionality for many years. The fourth generation of the sensor combines a total of five functions in one product. In addition to rain and light detection, the sensor enables solar and humidity measurement, as well as adjusting the light intensity of the head-up display.


The rain sensor can be used with a windscreen inclination of 20° to 54°, and is used to detect various rain situations and automatically control the front windscreen wipers. The light sensor controls when the low beam is switched on and off, such as in the dark or driving through a tunnel. When using the sensor for the head-up display, the brightness is measured in the area directly in front of the vehicle and the light intensity of the display is adjusted accordingly. The solar and humidity measurement helps control the air conditioning, in case of a fogged windscreen, for example.


The current version of the HELLA rain-light sensor has a further optimised design and impresses with its compact construction, which allows it to be used even under cramped installation conditions.

Product Advantages

  • The fourth generation in a long line of rain sensors by HELLA
  • Five functions in one product: Rain, light, solar and moisture measurements and also adjustment of the light intensity on the head-up display
  • Optimised design – extremely compact package space

Technical Data

Operating temperature -40 to +85 °C
Storage temperature -40 to +100 °C
Protection class IP 50
Protection class (in the area of fogging sensors) IP 20
Operating voltage 9 – 16 V
Overvoltage 24 V
Rated current consumption < 50 mA
Communication interface LIN 2.0
Weight < 17 g < 17 g

Program Overview

Variant Permitted windscreen thickness Permitted windscreen tilt Part number Packaging unit
Passenger cars 4 – 6 mm 20° – 36° on request -
Passenger cars (van) 4 – 6 mm 37° – 54° on request -


Variant Part number
Bracket for mounting with 3M adhesive tape Plastic 9XD 420 747-601
Bracket for mounting with PUR liquid adhesive Plastic 9XD 420 747-501
Bracket for mounting with 3M adhesive tape Sintered metal 9XD 420 747-007
Bracket for mounting with PUR liquid adhesive Sintered metal On request