Noise and walk test

2-12. Noise and walk test

system should be operated at the lowest RANGE control

setting that will give the required coverage. Operating

The noise level test and the walk test must be

the system below its maximum capability can result in

performed for each transceiver location. The noise

more consistent performance. Maximum efficiency in

level test checks out the adjacent turbulence and the

surveillance detection is obtained by adding another

walk test verifies the intended surveillance coverage.

transceiver to extend the range of a system rather than

stretch the existing system to its limits. Under no

Pretest condition.

All tests should be

conditions should the noise test exceed more than 0.15

conducted in the worst case situation with background

Vac when there is no human motion is any of the

turbulence at its maximum anticipated level.

Air

protected areas. Prior to the noise test and the walk test

conditioners, heaters, and machinery that would

for each transceiver perform the following adjustment

normally operate during the hours that protection is

and multimeter setting.

required should be turned on.

The only human

movement within the protected area should be that of

(1)

Set the RANGE control(s) of the

the walk tester.

transceiver(s) to coincide with the condition as listed in

table 2-2.

Pretest adjustment.

As a general rule, the

Table 2-2. Typical RANGE settings for varying number of transceivers.

(2) Set the multimeter (AN/USM-210) to

before proceeding

with

tests

read A.C. and the range selector switch to 2.5 V.

observations.

c. Location Test. The transceiver location is now

(2) If the multimeter reads greater than

ready to be checked for noise level and to be walk

0.15 Vac, check to see the cause of the major

tested.

contribution to the noise turning off air moving units,

heater and machinery one at a time and observe the

(1) Apply power to the processor and allow

noise level on the multimeter. If necessary, reduce the

to stabilize for approximately 30 seconds.

RANGE control setting to a noise level of 0.15 Vac or

reposition the transceiver to a different location of a less

NOTE

noisy or turbulent area in the room that is being

protected.

Each time power is applied to the

processor a stabilizing period of

(3) Walk through the entire area covered by

approximately 30 seconds must elapse

the transceiver and verify its adequacy in detection.

2-6