Castle Communication Technologies

P.O. Box 754        Lancaster, OH        43130        (614) 439-4039

998/998EX    
Fresnel PIR with Look-Down Zone

50' x 50' coverage
Optional coverage patterns (extra lenses included)
Horizontal and vertical pattern adjustment
Optional swivel mount bracket
Automatic temperature compensation
Alarm memory and case tamper (998EX)
Alternate polarity pulse count
EZ-Mount features for fast installation
SMD construction
White light filter
High RFI immunity
6 year over-the-counter warranty

Positioning of the lens of the look-down zone is critical to look-down performance. Typically, a PIR will have its look-down lens as an integral part of the outside housing, as seen on the left side of the figure. This creates two problems:

1. Detection can be compromised. A lens focuses its infrared energy at a fixed spot just like a magnifying glass or telescope. For best operation, this fixed spot in a motion detector is on the pyroelectric elements. When the PCB is moved vertically for coverage adjustment, this energy will be defocused except when the board is in just one particular
position. Less energy is collected and detection performance suffers.

2. Immunity to rodents is compromised. The long focal length (the distance from the lens to the pyro elements) causes the projected beam for the look-down zone to be small. As seen in the left figure, rodents can fill a large portion of the beam and generate a false alarm.

Ademco look-down designs overcome both problems by using a shorter focal length lens mounted very close to the detector as part of the circuit board, as shown on the right figure. When the PCB is shifted vertically for pattern coverage adjustment, infrared energy is always focused since the distance between the lens and the elements never changes. Because the lens is close to the element, the projected beam on the floor is now large compared to the size of a rodent. Avoid both detection and false alarm problems with Ademco look-down designs.

998/998EX Specifications:

Detection Method Passive Infrared

 Coverage 11 Standard Wide Angle Lens 50' x 50' (15m x 15m), 90º

Long Range Lens 100' x 10' (30m x 3m)

Pet Alley Lens (998 only) 50' x 70' (15m x 21m), 100º

Detection Pattern: Standard Lens: 18 zones (9 long range, 5 intermediate, and 4 short range)
Long Range: 5 zones, (1 long range, 2 intermediate, 2 short range)
Pet Alley: 12 zones Detector provides single "downward-looking" zone with all lenses
(downward-looking window must be masked when using pet alley lens)

 Pulse Count Installer-selectable, 1- or 2-event

 Detectable Walk Rate 0.5-5 ft/sec (.15-1.5m/sec)

 Mounting 7' to 8' nominal (2.1m-2.5m)

 Indicators Red LED with enable/disable link

Alarm Relay Form A, N.C. 5A contact rating @ 30V DC. 15 ohm protective resistor

Input Voltage 12 VDC nominal (voltage reversal makes PIR inoperative)

Current 15 mA (non-alarm), 17 mA (alarm)

 Operating Temp 14ºF to 122ºF (-10ºC to 50ºC)

 Operating Humidity Up to 95 RH (max.), non-condensing

 Dimensions 2/W x 4/H x 2" D(67mm x 111mm x 51mm)

MONITORING FOR YOUR ALARM SYSTEM AS LOW AS $ 12.50 PER MONTH!

Contact the webmaster by E-mail