The working principle of the system is: DPF filters the particulate matter (PM) in diesel engine exhaust, to make emission up to certain standard.

系统工作原理是：DPF过滤柴油机排气中的颗粒物（PM），从而使排放达到相应的标准。

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Ceramic wall flow filter is an effective carbon particulate matter purification device on the diesel engine vehicle.

壁流式陶瓷颗粒过滤器是柴油车上有效净化碳颗粒的装置。

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The diesel engine exhaust doubled the background particulate matter levels found outdoors at its peak.

BBC: Image of a smoke filled room