FINE PARTICLE SENSING SYSTEM

An object is to provide a particulate detection system which can properly detect the quantity of particulates contained in a gas and which can properly detect a state in which the injection quantities of compressed air and ions have decreased due to clogging of a nozzle or other causes. A particulate detection system 1 for detecting the quantity of particulates S contained in a gas EG includes a detection section 10, circuits 210, 240, 230, and a compressed air port 70. The detection section 10 includes an ion gas jetting source 11 which has a nozzle member 31 forming a nozzle 31N for jetting produced ions CP together with compressed air AK, a particulate electrification section 12 which forms a mixing region MX and a collection electrode 42, and an auxiliary electrode 53 for assisting collection of floating ions CPF. An auxiliary electrode potential PV3 is produced by a variable auxiliary electrode power supply circuit 240. The potential difference between the auxiliary electrode potential PV3 and a collection electrode potential PV1 is defined as a trap voltage Vt. The system 1 includes index detection means S54 - S5C for obtaining an index trap voltage Vt1-2 corresponding to a predetermined quantity of exhausted floating ions CPFH, and determination means S5F for determining whether or not the index trap voltage Vt1-2 is higher than a permissible voltage Vtmin.