A filter element sensor module having a housing, a sidewall of the housing including a recessed portion. The sensor module including a sensor assembly being provided within the housing about a sensor port interface being provided at one end of the housing. The sensor module also including processing circuitry being configured to receive signals from the sensor assembly and communication module, the communication module being configured to transmit one or more sensed parameters from the sensor assembly.

An air cleaner assembly having an oblong cross section shape and is shaped to cooperate with non-circular air filters. An intake tunnel passes around a portion of an exterior of a filter housing body and overlies an air inlet into the filter housing body. The intake tunnel initiates rotational or cyclonic movement of air directed into the filter assembly. A cover cooperates with a longitudinal end of the filter housing assembly and allows access to the non-circular air filter. The air cleaner assembly is constructed to allow visual inspection of the interior of the air cleaner assembly. The air cleaner assembly includes a filter body support that defines an air duct that communicates filtered air toward an underlying power tool or internal combustion engine and that at least partially supports the air filter assembly relative to the underlying equipment.

An air cleaner assembly having an oblong cross section shape and is shaped to cooperate with non-circular air filters. An intake tunnel passes around a portion of an exterior of a filter housing body and overlies an air inlet into the filter housing body. The intake tunnel initiates rotational or cyclonic movement of air directed into the filter assembly. A cover cooperates with a longitudinal end of the filter housing assembly and allows access to the non-circular air filter. The air cleaner assembly is constructed to allow visual inspection of the interior of the air cleaner assembly. The air cleaner assembly includes a filter body support that defines an air duct that communicates filtered air toward an underlying power tool or internal combustion engine and that at least partially supports the air filter assembly relative to the underlying equipment.

An air cleaner assembly with a restriction indicator includes a housing having an exterior surface around an interior volume. The housing includes a bore extending through a portion of the exterior surface of the housing surrounded by a bore wall protruding from the portion of the exterior surface. A receptacle wall of the housing is disposed around the bore wall and is radially spaced from the bore wall to form a channel between the bore wall and the receptacle wall. A restriction indicator measures a restriction in the interior volume and displays an indication of the restriction. The restriction indicator includes a stem that is at least partially insertable into the bore that engages an inner surface of the bore wall. One or more tabs of the restriction indicator are at least partially insertable in the channel and removably couple to the receptacle wall.

An air cleaner assembly with a restriction indicator includes a housing having an exterior surface around an interior volume. The housing includes a bore extending through a portion of the exterior surface of the housing surrounded by a bore wall protruding from the portion of the exterior surface. A receptacle wall of the housing is disposed around the bore wall and is radially spaced from the bore wall to form a channel between the bore wall and the receptacle wall. A restriction indicator measures a restriction in the interior volume and displays an indication of the restriction. The restriction indicator includes a stem that is at least partially insertable into the bore that engages an inner surface of the bore wall. One or more tabs of the restriction indicator are at least partially insertable in the channel and removably couple to the receptacle wall.

A method for establishing a permitted maximum differential pressure (p.sub.max) of an air filter (3) arranged in an intake tract (2) of an internal combustion engine (1), wherein a control reserve of the internal combustion engine (1) is determined and the maximum permissible differential pressure (p.sub.max) of the air filter (3) is established as a function of the determined control reserve.

Method for detecting an air filter condition, in particular for combustion engines, comprising the following steps: calculation of a linear regression over data-couples values, each comprising pressure drop value at the air filter and square of air flow value crossing the air filter, corresponding to said pressure drop value, in order to obtain an angular coefficient of the linear regression, comparison of the angular coefficient or of the function construed on the angular coefficient with at least one threshold in order to detect an operative condition of the air filter (FIG. 1).

Method for detecting an air filter condition, in particular for combustion engines, comprising the following steps: calculation of a linear regression over data-couples values, each comprising pressure drop value at the air filter and square of air flow value crossing the air filter, corresponding to said pressure drop value, in order to obtain an angular coefficient of the linear regression, comparison of the angular coefficient or of the function construed on the angular coefficient with at least one threshold in order to detect an operative condition of the air filter (FIG. 1).

Methods and systems are provided for diagnosing an air filter for a vehicle. In one example, a method may include actuating a motor to flow air through the air filter during engine off, and indicating air filter replacement based on an air pressure measurement while actuating the motor.

Methods and systems are provided for diagnosing an air filter for a vehicle. In one example, a method may include actuating a motor to flow air through the air filter during engine off, and indicating air filter replacement based on an air pressure measurement while actuating the motor.