Turbidity Sensor (Eco Sensor Iii, Auto-Sensor), B3/10; Figure 4-12: Turbidity Sensor Circuit - Miele G1000 Technical Information

Technical Information
4.3.6

Turbidity Sensor (ECO Sensor III, Auto-sensor), B3/10

Dishwashers from the G 1000/G 2000 generation are provided with one of two
turbidity sensors, depending on model:
The ECO sensor III measures the turbidity of the water and based on this result, the
wash blocks, temperatures and running times of automatic programs are modified. In
addition to this, the Auto-sensor has a microprocessor to evaluate the particle
measurement.
Principle of Operation
Water circulation and the presence of detergent cause bubbles to develop and
measurement technology cannot differentiate between such bubbles and suspended
soil particles. With the ECO sensor a proportion of the suds is directed into a bypass
channel, which is wider at the other end. This causes the flow rate to reduce and
hence the bubbles in the water to rise. The suspended soil particles in the water can
then be more accurately registered in the following measuring process.
A photoelectric barrier switch (IR diode (infrared) opposite a photo transistor) acts as
a turbidity sensor. Depending on the turbidity (Transparency) of the water, a certain
current flows through the phototransistor. This current is measured and processed by
the electronic unit, which then initiates the appropriate action. If the level of turbidity
passes certain thresholds, then depending on the soiling detected, the following
cleaning cycles are modified accordingly with regard to water quantity, program
duration and temperature.
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2
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Figure 4-12: Turbidity Sensor Circuit

Common 5 V
IR LED Cathode
Light Receiver Output (Emitter
G1000 / G2000 Dishwashers
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