Sensor probe assembly and method of forming

A method of forming an optical transmission flow cell comprising:

• printing a housing having a fluid pathway cavity disposed therethrough;
• the fluid pathway cavity including a first fluid pathway channel and a second fluid pathway channel;
• during the printing of the housing, lofting a first arcuate loft surface at a first transition between the first fluid pathway channel and an optical pathway cavity, and lofting a second arcuate loft surface at a second transition between the second fluid pathway channel and the optical pathway cavity;
• during the printing of the housing, forming the optical pathway cavity disposed through the housing and transverse to the fluid pathway cavity to create a fluid flow path through the first fluid pathway channel against the first arcuate loft surface, into the optical pathway cavity, and through the second fluid pathway channel against the second arcuate loft surface;
• wherein the optical pathway cavity is configured to cause a projection of light therethrough to be disposed through a fluid in the fluid flow path after passing through the first fluid pathway channel and against the first arcuate loft surface to prevent formation of air pockets within the fluid in the optical pathway cavity.