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The Motion Detectors use
ultrasound to measure distance. Ultrasonic pulses are
emitted by the Motion Detector, reflected from a target,
and then detected by the device. The time it takes for
the reflected pulses to return is used to calculate
position, velocity, and acceleration. This allows you to
study the motion of objects such as a person walking, a
ball in free fall, or a cart on a ramp.
Some of the Motion Detectors can measure objects as
close as 15 cm to the detector and as far away as 6 m.
The short minimum target distance allows objects to get
closer to the detector, which reduces stray reflections.
A special Track mode switch tailors the sensitivity for
dynamics carts on tracks for lower noise and higher
quality data. The Motion Detector attaches easily to the
some Dynamics Track programs, and has a pivoting head
and rubber feet for ease of use when not attached to a
dynamics track. The cable is removable, so you can use
the Motion Detector with other interfaces with a
separate cable.There are
several type and brand Motion Detectors. You can use our
site to find your motion detector. You can compare and
find your Motion Detector at our catalog easily. |
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Analog Single-Optic PIR Motion Detector |
MG-PMD75 Digital Dual-Optic High-Performance PIR
(40kg/90lb True Pet Immunity) |
Optex RCTD-10U Wireless Annunciator System |
Motion Detector Kit |
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X10 PRO Dual Floodlight Motion Detector |
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Motion
Sensors and Motion Sensing |
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The "motion sensing" feature on most
lights (and security systems) is a passive system that detects
infrared energy. These sensors are therefore known as PIR
(passive infrared) detectors or pyroelectric sensors. In order
to make a sensor that can detect a human being, you need to make
the sensor sensitive to the temperature of a human body. Humans,
having a skin temperature of about 93 degrees F, radiate
infrared energy with a wavelength between 9 and 10 micrometers.
Therefore, the sensors are typically sensitive in the range of 8
to 12 micrometers.
If you have a burglar alarm with
motion sensors, you may have noticed that the motion sensors
cannot "see" you when you are outside looking through a window.
That is because glass is not very transparent to infrared
energy. This, by the way, is the basis of a greenhouse. Light
passes through the glass into the greenhouse and heats things up
inside the greenhouse. The glass is then opaque to the infrared
energy these heated things are emitting, so the heat is trapped
inside the greenhouse. It makes sense that a motion detector
sensitive to infrared energy cannot see through glass windows.
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MOTION
DETECTORS
