Kenmore 630.13952 Manual page 22

COMPONENTS
Optical rinse-aid sensors
Optical rinse-aid sensors determine if rinse-aid is present using a light beam
and sensor.
TIP:
adequately to show rinse-aid isn't needed.
702_58300000149896_ara_en_b
It's possible for some clear rinse-aid brands to not diffuse light
With rinse-aid present, the optical
receiver senses a diffused light
beam.
When rinse-aid has run out, the
optical receiver senses a strong
light beam.