The Water in Fuel Sensor or WiF sensor indicates the presence of water in the fuel. It is installed in the
fuel filter
A fuel filter is a filter used to screens out foreign particles or liquids from the fuel. Most internal combustion engines use a fuel filter, in order to protect the components in the fuel system.
Filters for foreign particles
Unfiltered fuel ...
and when the water level in the water separator reaches the warning level, the Wif sends an electrical signal to the
ECU or to dashboard (lamp).
The WiF is used especially in the
Common Rail engines to avoid the
Fuel injector
Fuel injection is the introduction of fuel in an internal combustion engine, most commonly automotive engines, by the means of an injector. This article focuses on fuel injection in reciprocating piston and Wankel rotary engines.
All comp ...
damage.
The WiF sensor uses the difference of
electric conductivity
Electrical resistivity (also called specific electrical resistance or volume resistivity) is a fundamental property of a material that measures how strongly it resists electric current. A low resistivity indicates a material that readily allows ...
of water compared to diesel and gasoline to determine the presence of water. The WiF sensor can consist of two electrodes that reads the level of resistance in the fluid or between the ground and the electrode.
First generation WiF sensors use a potting resin to isolate the electronic circuit, while the latest generation of Wif sensors (the WS3 sensor in
Surface-mount technology) are made totally without leakage using an innovative co-moulding process.
The latest generation of WiF sensors have a high resistance to vibrations and to thermal excursion cycles.
The main automotive WiF designer and producer is SMP Poland.
References
Auto parts
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