Truck & Bus DEF (AdBlue) Sending Unit - TV3-S - a DEF sending unit fitted to trucks and buses.

The sending unit features a level sensor, DEF suction & return and ports for engine coolant that flows through a coiled heater pipe around the sensor to ensure fast and even heating of the DEF in cold conditions.

With so many variables; length, port size/thread, vent, resistance, filter etc., there are literally hundreds of different versions of this sending unit so it's always best to give us a call and we can make sure that we supply you with the correct unit for your vehicle.

For replacement sending units we need to know the make and model of truck it's going into and also the manufacturer or Wema part number. This can be found stamped into the top of the sending unit. If in doubt, send us a photo for identification.

For new applications we need to know:

• Manufacturer (Scania, Volvo, M.A.N. etc)
• Length of sensor (and/or height of tank)?
• Resistance value (Empty Ohm (i.e. 10) and Full Ohm (i.e.180) =>10-180 ohm)?
• Fitting for suction – dimension and/or quick fit?
• Fitting for return – dimension and/or quick fit?
• Fitting for heater – dimension?
• Fitting for heater return – dimension?
• Electronic connector (e.g. DIN 2-4 pin or other)?

Designed to meet global emission legislations

Global emission legislations for diesel engines are becoming increasingly stringent. While the exhaust gas composition requirements for prior iterations of emission legislation could be met with improvements in the engine’s combustion process, the next issue of European, North American and Japanese emission limits will require more rigorous measures, mainly employment of selective catalytic reduction (SCR) technology.

Wema, being the world wide leading manufacturer of DEF sensors, supplying 95% of all European SCR equipped trucks, makes an important contribution to efficient SCR operation. All sensors are custom made in terms
of length, dimensions of tubes, thawing capabilities, filter and electrical characteristics and can, furthermore be integrated with a Wema urea quality sensor.

The urea quality sensor addresses quality control concerns by ensuring a specific quality of urea is delivered into the exhaust gas stream. The introduction of a urea quality sensor into the SCR system

also reduces the risk of tampering or accidental mis-filling and helps ensure compliance, thus satisfying concerns of users and legislators alike. This contributes to the overall success of SCR as a NOx reduction technology.

One single unit- reducing for cost efficiency :

Interfacing the DEF quality sensor with a standard Wema DEF sensor, allows us to offer our customer a complete system, interfaced into one unit with features such as:

· High and low level indicator
· Suction and return of DEF
· Heating tubes for melting of frozen

DEF
· Temperature
· Filter
· Air vent
· DEF quality measurements · CANBus output for meeting

On- Board Diagnostic (OBD) requirement

Why use a urea quality sensor?

The benefits derived from Wema Urea quality sensor can be described from three aspects:

• · Safety aspect
• · Truck operator aspect

• · Truck manufacturer aspect

  Common feature for these aspects has proven to be:

• · Diesel fuel is accidentally put on the DEF tank.
• · Salt water is deliberately put on the DEF tank
• · Truck driver is topping up the DEF tank with water
• · Canisters are refilled and reused and DEF decanted to improper containers

• · Rogue suppliers producing non-DIN specification DEF

  Actually, industry sources indicate that up to 50% of truck drivers in certain European countries do not use DEF on their SCR trucks.

  The consequences can be summarized as follows:

• · Explosions and fire in catalyst due to

  diesel in DEF tank

• · Engine damage due to diesel in DEF

  tank

· SCR ring gasket damages due to diesel in DEF tank

· Clogging of catalyst due to diesel or non compliance DEF

· Non compliance DEF will not meet emission legislations

· Non compliance DEF can incur costly torque penalties

· Non compliance DEF can incur financial penalties from authorities

· Non compliance DEF can cause warranty claims

· Running with poor quality DEF or diluted DEF 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 DEF tank
· It can alarm the DEF dozing pump,

enabling it to stop injection of diesel and thereby preventing hazardous situations.

· It will immediately detect any non- compliance DEF

· It can instruct dozing unit to stop injection and thereby preventing any non compliance DEF 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 DEF