Bosch Appliances DS938Z manual Optical Module Optical Module Masking, Overview

If the time period selected has elapsed from the last alarm, the LED will flash two times and the Trouble Output will activate.

Setting the Motion Monitor timer to shorter periods can be used to force a protection walk test of remotely located zones.

It is recommended that the 30 day timer be selected. This verifies that the unit is operational and avoids nuisance trouble conditions caused by holi- days, vacations, etc.

7 Optical Module

7.1 Optical Module Masking

Peel-off masks are provided with the unit for each segment of the opti- cal module to allow for customized coverage, or to block out areas of objects that may cause thermal disturbances. The mask is self-adhesive and pre-cut in the shape of the optical module.

The location of the zone to be masked depends on the position of the detector. Therefore, determine the mirror surface to be masked before removing the mirror from the detector.

To block out a particular zone or group of zones, peel off a section of the mask that corresponds to the appropriate zone, and stick it on the mirror segment. Before attempting any masking, be sure the chosen mirror surface is the correct one. Refer to Figure 7.1 to identify mirror segments and zones.

NOTICE!

When disabling the look-down segment, do not mask segment 5 direct- ly as this will disable the entire detector. Instead, mask the segment on the dome directly below segment 5.

SIDE

VIEW

AR8-13

TOP VIEW

O

P

A

B

C

P

A

B

N

O

C

D

D

M-4

E-4

N

M-2

M-1

5

E-1

E-2

M

E

M-3

E-3

M

E

L

K

G

F

J

I

H

L

F

K

G

13-AR8

1

2

3

4

5

4

3

2

J

I

H

1

Figure 7.1: Mirror module to pattern reference

NOTICE!

When attempting to remove any masking, many adhesives will either destroy the mirror surface or leave enough residue behind to reduce coverage performance.

1 Overview

The DS938Z is a high performance passive infrared intrusion detector. It is equipped with advanced PIR detection and supervision circuits and is de- signed to provide an alarm condition upon detection of an intruder passing through its area of coverage.

Employing balanced dual-opposed sensing elements, the DS938Z passive infrared (PIR) detector makes use of the fact that all objects give off (emit) infrared energy, and that the warmer an object is, the greater the amount of infrared energy given off. The DS938Z uses PIR receiver technology designed to detect the change in infrared energy caused when a target of a different temperature from a stable background passes through its field of coverage.

The coverage pattern consists of sensor zones arranged to form a circular coverage pattern.

Using Motion Analyzer II circuitry, the detector must first see a change in infrared energy in one zone followed by a change of energy in the remain- ing zone. Therefore, disturbances that occur in only one finger do not constitute motion and are ignored. This “catch sensitivity” may be changed in the field by the installer to provide the degree of sensitivity required by the installation.

Self-test and supervision circuits provide reliable operation in a variety of installation environments. The result is a highly advanced detector offering superior performance with freedom from false alarms.

Specifications

Dimensions	3.5 in. x 5.25 in. (8.9 cm x 13.3 cm)
(HxDia)
Input	6.0 to 15.0 VDC; 5 mA standby, 20 mA in alarm with LEDs enabled. Use only an Approved
Power	Limited Power Source.
Alarm Relay	Silent-operating Form “C” relay. Contacts rated <100 mA, 25 VDC, 2.5W maximum, <20
	Ohm closed for DC resistive loads.
Tamper	Contacts rated at 28 VDC, 125 mA maximum, <1 Ohm. Connect tamper circuit to a 24-
	hour protection circuit.
Trouble	Maximum current load is 25 mA.
Output
Optional	TC6000 test cord.
Accessory

10 © 2012 Bosch Security Systems, Inc. F.01U.263.663 01 05.2012 3