Online dust particle counter

The invention discloses an on-line dust particle counter, and relates to the technical field of dust particle counting, the on-line dust particle counter comprises a shell, a detection assembly, a sampling mechanism, a measurement cavity, an air inlet pipe and an air blowing isolation assembly, the detection assembly, the measurement cavity, the air inlet pipe and the air blowing isolation assembly are installed in the shell, one end of the sampling mechanism is installed on one side outside the shell, and the other end of the sampling mechanism is installed on the other side outside the shell. One end of the measuring cavity is connected with the other end of the air inlet pipe through an air blowing isolation assembly, at least one air inlet nozzle is arranged on the peripheral side of the air blowing isolation assembly, an annular air blowing nozzle is arranged at one end of the air blowing isolation assembly, the annular air blowing nozzle is communicated with the air inlet nozzle, and the annular air blo