The DEF Quality Sensor (DQS-1A) includes a unique capacitive sensing element working with a level/temperature sensor for detecting DEF level, DEF quality, errors in the DEF quality sensor, and issues in a dosing system. In detecting DEF level, impedance of the capacitive sensing element is used in improving sensing performance of the DEF level sensor, while in detecting DEF quality and errors in the DEF quality sensor, an expected impedance range with an upper boundary value and a lower boundary value is calculated, and a fault is generated when the measured impedance value is out of the expected impedance range calculated using sensing values obtained from the DEF level sensor. The DEF quality sensor can also be used in a dosing system for detecting system issues, and the results can be used for further isolating errors in the dosing system.

Compared to some other types of DEF quality sensors, such as resonant tuning fork sensors and capacitive impedance sensors, our sensor is inexpensive, more reliable, and multifunctional. This technology is patent pending (US 13/938,230).

The sensor controller has an analog interface and an optional CAN/J1939 interface. Outputs of the sensor include Urea Temperature, Urea Level, Urea Quality, and an Error Flag.


The DQS-1A DEF Quality Sensor:



Applications of the DQS-1A DEF Quality Sensor:







—Measurement range :0%-50%;

—Response time :(T90<1s ) , set fault < 3s;
—Working temperature:-40-85°C,humidity,0-100%RH;
—Voltage supply:+5V;current:<100mA;
—DEF level sensing:5% (adjustable) step;
—DEF quality sensing:(±3% ); by default set fault when urea concentration <25% or >40%;
—DEF temperature sensing range:-40-85°C;accuracy: ±1°C ,resolution:0.1°C;
—Ambient temperature sensing range:-40-85°C;accuracy: ±1°C ,resolution:0.1°C;
—Ambient humidity sensing range (optional):0-99%RH,accuracy:±2%,resolution:0.5%;
—Interface:4 channels 0.5-4.5V analog output/CAN/J1939;
—Vibration:ISO 16750-3;
—EMC: ISO 11452 -2, -4, -5.



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