EXHAUST FILTER BACKPRESSURE INDICATOR.

摘要

An exhaust filter backpressure indicator includes a sensor for measuring the backpressure and the exhaust system. The sensor sends a signal which is processed for indicating that an exhaust filter element is filled. The indicator includes a timer so that a signal corresponding to pressure must be maintained for a predetermined period of time before the filled element is indicated. The apparatus may also include high and low frequency discriminators to process signals within predetermined signal frequency ranges corresponding to engine operating speeds. Therefore, depending on the operation of the vehicle, the element will be indicated as being filled at either high engine speed operation or low engine speed operation.