Visible products of combustion are best detected by a(n) ________ detector.

The most effective detector for identifying visible products of combustion is the photoelectric detector. This type of smoke detector operates by using a light source and a light-sensitive sensor. When smoke particles from combustion enter the detection chamber, they scatter the light beam, which triggers the alarm. Since visible smoke is typically associated with smoldering fires that produce larger particles, the photoelectric detector is particularly sensitive to these conditions.

In contrast, ionization detectors are designed to respond more quickly to fast-flaming fires, which may not produce visible smoke. They work by ionizing the air in a sensing chamber and are typically more responsive to smaller particulate matter, but less effective at detecting larger, visible smoke particles.

Ultraviolet detectors are primarily used to detect the presence of flames and are less effective at identifying smoke. They are sensitive to the ultraviolet light emitted by flames rather than the byproducts of combustion in the form of smoke.

Infrared detectors can detect heat and changes in temperature associated with fires but are not specifically designed for detecting visible smoke.

Thus, the photoelectric detector is the most suitable choice for detecting visible products of combustion due to its sensitivity to larger smoke particles commonly produced by smoldering fires.