Temperature
Background suppression strip point sensor LQ31-BK100N, red light detection range 100mm
Light spot type: visible strip light spot
Detection distance: 30-100mm adjustable
Output mode: NPN/normally open/normally closed

Spot size: about 2mm
*You can't actually see the beam, but you can see the light spot

Theory: Optical Sensors

Type: Photoelectric sensor
Output: switch sensor