• Approved by the Energy Savings Trust to meet London nrmm LEZ and HS2 requirements
  • Full range of sizes and regeneration types to retrofit any machine type and application
  • High quality construction and components to give good durability and trouble free operation
  • European market leader with 25 Years of experience and more than 10,000 nrmm retrofit systems sold
Image of the PIO-CAN
PIO-CAN Back Pressure Monitor

BISAF is the UK agent for Johnson Matthey’s range of retrofit emissions systems for construction machines. These include a range of filter sizes and regeneration types that mean that a system can be retrofitted to any machine, regardless of size or application.

These are full flow filters that are intended for permanent installation. They are listed on the Energy Savings Trust register for use in the London NRMM LEZ, and for HS2 requirements. They are also VERT® approved.


All Johnson Matthey DPFs come with a back pressure monitor, datalogger and systems controller, the PIO-CAN. A sensor is installed in the filter inlet, with the electronic monitor usually located close to the operator in the cab. The visual display shows real time back pressure with warnings when the pressure reaches set levels. Back pressure levels are recorded so that they can be retrieved and any problems diagnosed. For active systems, the PIO-CAN also contains the systems control functions for easy operation.

BISAF also offers a telematic system that allows us to monitor your DPF system remotely. If you choose to take this telematic system, we will be able to read the data that is captured on the PIO CAN, including back pressure over the filter, regeneration events and any fault codes. We offer a variety of subscription services to monitor these systems on a regular basis and will let you know if there are any problems or if the machine operator needs to take any action. This service can help you avoid expensive repairs that can result from the filter not being regenerated often enough and becoming blocked with soot.


Some of the Machines Fitted With  Johnson Matthey DPFs

How the CRT® System Works


Johnson Matthey invented the CRT® which is the most widely used and successful retrofit filter technology. This uses a special catalyst in front of the filter to convert some of the NO in the exhaust gas to NO2. The NO2 reacts with the soot on the filter at normal exhaust temperatures to continually remove the particulate as it is filtered from the exhaust gas. For this technology to work successfully, the exhaust gas needs to be above 260oC for 50% of the time. This is normally achieved when a machine regularly uses a significant amount of power to complete tasks. The operating window can be extended to lower temperatures (50% of the time above 240oC) by using the CCRT® that has a catalyst coated filter as well as the pre-catalyst. The DPF CSF just uses a catalyst coated filter and has the advantage of being shorter in length than the CRT® system but needs higher operating temperatures to regenerate successfully.

The DPFi

This is an active system that intermittently employs electrical heating to burn off the soot from the filter. In this system, the back pressure of the filter is monitored and when this reaches a certain level the operator is notified that the filter should be regenerated. This involves turning off the engine, connecting an external power source and waiting approximately one hour for the automated cycle to be completed. The monitor will inform the operator that the cycle has finished successfully and the machine will be ready to use again.


This is another active system that uses a Diesel fuelled burner to remove the soot accumulated on the filter. The back pressure monitor in the cab will alert the operator when the system needs a regeneration, the operator will need to turn off the engine and then initiate the burner cycle which lasts about 30 minutes before the machine is ready to be used again.


This is an exchangeable filter system in which a filter that has accumulated soot is changed for a clean filter. The removed filter can then be regenerated on an external regeneration station also available from Johnson Matthey.


This is a system that uses a fuel additive that is automatically dosed into the machine’s fuel tank. It is then burnt in the engine before being deposited in the filter along with the soot. This helps the soot to burn at lower temperatures, above 380oC. As these temperatures require the engine to be working hard on a regular basis, this system is only used in limited applications.

Please contact us to discuss the best Johnson Matthey DPF for your application.