Global emission legislations for the automotive industry are becoming increasingly stringent. While the exhaust gas composition requirements for prior iterations of emission legislations could be met with improvements in the engine's combustion process, the next issue of Japanese, North American and European emission limits will require more rigorous meaures, mainly employment of Selective Catalytic Reduction (SCR) technology.
Wema, being the world wide leading manufacturer of AdBlue sensors, supplying 95% of all European SCR equipped trucks, makes an important contribution to efficient SCR operation.
All Wema AdBlue sensors are custom made in terms of length, dimensions of tubes, thawing capabilities, filter and electrical characteristics. Furthermore, a urea quality sensor can be interfaced if required.
Our current product portfolio includes a wide range of tailor made solutions for OEMs and tank producers. The AdBlue sensors are made of acid proof steel and can combine level measurement with:
All sensors can be custom made in terms of; filter and filter position, dimensions of tubes, lengths, characteristics (ohm), cable length/type and electrical connections.
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| Level sensor with suction and return for AdBlue. type TVN | Level sensor with suction and return for AdBlue. type TV2 | Level sensor with suction and return for AdBlue. type TKD | Level sensor with suction and return for AdBlue. type TZI |
To ensure emissions compliance with JP 09, EPA 10 and EURO VI, Wema has, during the past four years developed a platform technology for continuously measurements of urea quality.
The primary technology behind this innovation is a Ultrasound based platform that accurately measures the speed of sound of the fluid being present in the AdBlue tank. The urea quality sensor sensor is designed for on-line use, has a tamper-resistant design and will eliminate any use of non-compliance AdBlue (DEF). Furthermore, the sensor has a durable design according to the requirements set in JP 09, EPA 10 and EURO VI.
Interfacing the quality sensor with a Wema AdBlue level sensor, allows Wema to offer its customers a complete system, interfaced into one unit with features such as:
The benefits derived from a urea quality sensor can be described from three aspects:
• Safety aspect
• Truck operator aspect
• Truck manufacturer aspect
Common features for these three aspects have proven to be:
• Diesel fuel is accidentally put on the AdBlue tank
• Salt water is deliberately put on the AdBlue tank
• Truck driver is topping up the AdBlue tank with water
• AdBlue canisters are refilled and reused
• Rogue suppliers producing non-DIN specification AdBlue
Actually, industry sources indicate that up to 50% of truck drivers in certain European countries do not use AdBlue on the SCR trucks.
The consequences of the above can be summarized as follows:
• Explosions and fire in the catalyst due to diesel in the AdBlue tank
• Engine damage due to diesel in the AdBlue tank
• SCR ring gasket damages due to Diesel in the AdBlue tank
• Clogging of catalyst due to non-compliance AdBlue
• Non-compliance AdBlue will not meet emission legislations
• Non-compliance AdBlue can incur costly torque penalties
• Non-compliance AdBlue can incur financial penalties from authorities
• Non-compliance AdBlue can incur warranty claims
• Running with poor quality AdBlue or diluted AdBlue may cause transport companies to suffer damage to their reputation for corporate responsibility.
The Urea quality sensor provides the following benefits:
• It detects immediately if diesel fuel is present in the AdBlue tank
• It can alarm the AdBlue dozing pump, enabling it to stop injection of diesel and thereby preventing hazardous situations
• It will immediately detect any non-compliance AdBlue
• It can instruct dozing unit to stop injection and thereby preventing any non-compliance AdBlue from entering the catalyst.
• It will report by CanBus to OBD any discrepancy from standard settings
• It will assist in roadside checks or during annual testing by reporting the use of any non-compliance AdBlue

