Vl1 Mounting And The Movement Sensor - Securesight VL1 Manual

VL1 mounting and the movement sensor

Passive Infra Red (PIR) sensors detect changes in infra-red radiation in
the form of heat given off by objects such as people, cars and animals.
The larger the object the more infra-red it emits. Your VL1 has an angle
of sensitivity of approximately 65 degrees and approximately 9m range.
©Securesight 2009 E&OE Issue 1.0
To focus the
energy to its
sensor your VL1
uses a Fresnel lens.
This divides the
area into a number
of zones, both
vertical and
horizontal.
PIR sensors detect
moving hot objects
as they cross zones.
Thus they are most
sensitive to
movement across
the area of
sensitivity and
least sensitive to
movement towards
the sensor.
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