Exhaust gas particle sensor

摘要

An exhaust gas particle sensor (1) has an inlet tube (3) and a sensing region (4) having different cross sections and linked by a transition region (4A) including a number of baffles (7) arranged so that the time taken for gas to travel from the inlet tube (3) to the sensing region (4) is substantially independent of the position of the gas across the inlet tube (3). The sensor (1) operates by measuring the opacity of the exhaust gas using a light beam (6) which passes in and out of the sensing region through windows (23), the exhaust gas being prevented from impinging on each window (23) by a double air curtain.