When installed, the Nett Technologies' PTLOG™150 engine exhaust backpressure monitor and alarm is a valuable tool to alert operators to plugging problems with Diesel Particulate Filters (DPFs) or other exhaust emission control devices. DPFs physically trap diesel particulate matter (soot).
The soot load on the filter and the associated pressure drop (backpressure) will fluctuate depending on the duty cycle of the vehicle and its exhaust temperature. The general rule is that installations with lower exhaust temperatures regenerate slower and experience higher pressure drop in the filter.
The accumulated soot is oxidized in the filter during regular operation of the engine. For about 25-30% of the engine operating time, the exhaust temperatures must be at least 275-300°C (530-575°F) for proper filter regeneration when ULSD (ultra-low sulfur diesel) fuel is used. The exact temperature requirements change with engine technology, with
installations on older, dirty engines requiring higher exhaust temperatures for regeneration.
For example, filters installed on older off-highway engines with high DPM emissions (e.g., >=0.30 g/bhp-hr) may require temperatures of 325-400°C (620-750°F). The regeneration also depends on other factors, such as the vehicle duty cycle, filter sizing and type of diesel fuel used. ULSD fuel (S < 15 ppm wt.) is now widely available and should be used whenever possible with any diesel particulate filter.
Vehicles operating under light duty cycles with insufficient exhaust temperatures will experience increasing accumulation of soot leading to excessive back pressure and filter overload. That condition can result either in complete clogging of the unit or an “uncontrolled regeneration”. The uncontrolled regeneration occurs when an excessive soot load ignites and rapidly burns producing an enormous heat release which can cause thermal cracking or melting of the filter material.
The Nett PTLOG™150 engine exhaust back pressure monitor and alarm continuously checks the exhaust back-pressure level of vehicles equipped with a Nett Diesel Particulate Filter. If the engine back-pressure exceeds the PTLOG™150’s pre-set levels, yellow and red LEDs will light-up to warn the operator. The monitor also has relay triggers to operate additional relay-controlled indicator lights, audible alarms or other devices if the yellow or red LEDs illuminate.
The PTLOG™150 system can monitor the back pressure of any exhaust system provided a 1/8” N.P.T. fitting (female) is installed upstream of any restrictions (exhaust emissions control device or muffler). All Nett catalytic converters, catalytic mufflers and Diesel Particulate Filters (DPFs) come with a pre-installed 1/8” N.P.T. fitting suitable for use with the PTLOG™150.
An ignition switched +12V or +24V power source is required for the PTLOG™150 electronic control module.
For the installation details and part numbers please check our Document Downloads section on the right side of this page. Or contact one of our customer service representatives today at our toll-free number 1-800-361-6388.