Optical particle sensor with exhaust-cooled optical source

A method for cooling an optical source of a particle sensor comprising:

• a. providing said particle sensor comprising:
• i. a sample chamber having an inlet orifice for receiving an input flow of said fluid sample and an outlet orifice for conducting an exhaust flow said fluid sample out of said sample chamber;
• and
• ii. an optical source provided in optical communication with said sample chamber;
• and
• b. providing an outlet passage in fluid communication with said outlet orifice of said sample chamber for receiving at least a portion of said exhaust flow of said fluid sample from said sample chamber;
• said outlet passage having a portion in thermal contact with said optical source;
• and
• c. flowing said fluid sample through said sample chamber and said outlet passage, thereby generating said input flow of sample fluid and said exhaust flow of sample fluid;
• wherein thermal exchange between said at least a portion of exhaust flow of sample fluid flowing through said outlet passage and said optical source cools said optical source.

A method of making a self-cooling particle sensor comprising:

• a. providing an optical source in optical contact with a sample chamber;
• b. providing an outlet passage that collects at least a portion of sample fluid from said sample chamber;
• and
• c. configuring said outlet passage such that said sample fluid within said outlet passage thermally contacts said optical source to provide self-cooling of the particle sensor.

A particle sensor for sensing particles in a fluid sample, said sensor comprising:

• a. a sample chamber having an inlet orifice for receiving a flow of said fluid sample and an outlet orifice for conducting said fluid sample out of said sample chamber;
• b. an optical source provided in optical communication with said sample chamber;
• and
• c. an outlet passage in fluid communication with said outlet orifice for receiving at least a portion of said flow of fluid sample from said sample chamber;
• said outlet passage having a portion in thermal contact with said optical source;
• wherein thermal exchange between said flow of sample fluid in said outlet passage and said optical source is capable of cooling said optical source
• wherein said outlet passage portion in thermal contact with said optical source comprises a plenum, said plenum comprising:
• a plenum inlet orifice for receiving flow of said fluid sample;
• a plenum outlet orifice for conducting said fluid sample out of said plenum;
• inlet tubing having a first end connected to said plenum inlet orifice and a second end connected to said sample chamber outlet or said outlet passage for introducing sample fluid to said plenum inlet orifice;
• and
• outlet tubing having a first end connected to said plenum outlet orifice and a second end connected to an exhaust orifice for transporting fluid sample out of said sensor.

A particle sensor for sensing particles in a fluid sample, said sensor comprising:

• a. a sample chamber having an inlet orifice for receiving a flow of said fluid sample and an outlet orifice for conducting said fluid sample out of said sample chamber;
• b. an optical source provided in optical communication with said sample chamber;
• and
• c. an outlet passage in fluid communication with said outlet orifice for receiving at least a portion of said flow of fluid sample from said sample chamber;
• said outlet passage having a portion in thermal contact with said optical source;
• wherein thermal exchange between said flow of sample fluid in said outlet passage and said optical source is capable of cooling said optical source.
• wherein the particle sensor has an optical source operating temperature, wherein said outlet passage portion in thermal contact with said optical source comprises a heat sink having an inlet heat sink orifice and outlet heat sink orifice, said fluid sample at said inlet heat sink orifice having an inlet temperature, wherein said inlet temperature is less than said optical source operating temperature.