Pioneer ND-PS1 Instructions Manual page 4

LIMITATIONS
Fig 1
Fig 2
Fig 1: Object position may be different from the displayed distance due to the sensor position, obstacle,
shape, or reflection.
If an object is too high
If the object is very small
When backing up downhill
Fig 2: Objects may not be detected properly in the following conditions.
Smooth slope
Smooth round objects
Objects that absorb waves (e.g. cotton)