Download Smoke Detector Test Results

Smoke Detector Test Results
Purpose:
This document contains the test results for Phase 2 detector.
Summary:
The smoke detector is working well over the target power supply voltage range. One area that needs to
be improved is getting the standby current down below 42uA. The 85uA current drain doesn’t seem to
be due to AFE/external circuitry, but is probably due to MCU settings. Outside, near incident or indirect
sunlight, the smoke detector may require additional enclosure to shield it from ambient IR light sources.
Inside, fluorescent light sources don’t have much effect on the smoke sensor.
Test Results as per Test Spec:
TEST
RESULTS
1. The Smoke sensor will be held with
the PCB in a horizontal position with
the IR emitter and IR photodiode
pointing down toward the floor (to
capture smoke particles wafting
upwards from combusting
materials). Testing will be done with
IR Emitter and IR Photodiode
enclosed in an Optical chamber
(such as GE SECURITY 211,
Replaceable Optical Chambers for
ESL Smoke Detectors for ESL 300,
400, 500, 500N, 700 and TS7
The smoke detector is
housed in a shoe box to
isolate it from day light
which increases the
background IR.
The optical chamber is
inside the shoe box, but
the PCB circuitry is outside
of the shoebox for easier
measurement.
EXPLANATION
2. One of two possible
smoke/simulated smoke sources
can be used:
a. Simulated smoke from an
aerosol can (examples:
Esl/Interlogix brand –
“Smoke in a Can”, or HSI
Fire and Safety Group
Model No. 25S – “Smoke
Check”)
b. Combustible materials, such
as a lit match that is
extinguished or
continuously burning
incense stick
1. Tested with threaded
paper placed inside
optical chamber. And
successful increase
receiver op-amp
output peak voltage
from 2.2V to 3V.
2. Tested with incense. It
takes a lot of smoke to
trigger alarm. Also it is
susceptible to sunlight
even with indirect
sunlight. Need to place
the whole system in a
dark enclosure.
3. MikeC.(10Mar2014)
Smoke sensor works
well with “Smoke
Check” and “Smoke-Ina-Can” brand spray
cans. After about 0.51 second of Smoke
spray the alarm acts
within 3 seconds and
turns on alarm for
multiple cycles of
6seconds ON and
3seconds OFF. This
alarm condition
repeats for 6-7 cycles
of 9 seconds each
before returning to
Alarm OFF condition.
Sunlight or
bright day
light increases
background
IR. So the base
line of the
signal
increases
from 0.8V to
1.3V.
3. Confirm that when detecting smoke
> 9 seconds +/-10% (3 consecutive
samples at 3 second sample rate) ,
detector will sound a buzzer/alarm
for a minimum period of 10 second
(+/-10%), followed by 5 second (+/10%) alarm after the end of smoke
detection. Confirm in the presence
of continuously detected smoke the
alarm will sound continuously.
Smoke cannot be turn on
and off instantly. And
depend on different
smoke type, incense
smoke is white smoke,
and not thick enough in
the beginning, It take
about a minute after insert
incense to testing chamber
before alarm went off.
Current code
looks for 1
sample for the
alarm
condition.
This is
because with
real smoke, 3
consecutive
alarm
condition may
MikeC.(10Mar2014) The
alarm sounds with
multiple cycles of
9seconds (6second Alarm
ON and 3seconds of Alarm
OFF) during Alarm period.
4. Confirm that if continuous smoke is
detected for more than 9 seconds
(+/-10%), but less than 60 seconds,
pressing SW1 on Smoke Sensor
board should defeat the alarm. (This
is commonly called the “HUSH”
button on consumer smoke alarms).
Confirm if smoke is
present/continuously detected for
60 second (+/10%) from initial
detection, the Smoke alarm will
sound and HUSH mode will be
inhibited. Then the alarm will not
turn off until 5 second (+/-10%)
elapsed after smoke is NOT
detected.
Hush mode implemented.
5. Confirm that pushing the SW1
button (added on the Phase 2
Sensor sensor board) when no
smoke is present will sound the
alarm as long as the button is
pressed and turn off when SW1
button is released (assuming no
smoke alarm is indicated on the
sensor).
6. Confirm that continuous powering
of the Smoke alarm for a 24 hour
period will not produce a false alarm
when no smoke is present. This can
be confirmed by a output port pin
that is reset to low state at
Tested ok.
MikeC.(10Mar2014)
Pushing SW1 momentarily
tests the Alarm buzzer
when pushed.
MikeC.(10Mar2014)
Pushing SW1 momentarily
tests the Alarm buzzer
when pushed. When the
alarm is sounding, pushing
the SW1 button defeats
the alarm
MikeC.(10Mar2014) Not
implemented.
take longer
time to
indicate the
alarm or miss
the smoke
condition.
With this
setting we did
not see false
alarm
condition in
18 hours
testing.
beginning of test and remains low at
end of 24hour period, or latched at
high state if false alarm detected at
any time during the 24hour false
alarm test period.
7. Current drain measurements and
associated duty cycles for each type
MCU operation will be measured for
the Smoke sensor operation in:
a. Standby mode with no
smoke in presence of the
sensor. Target is to achieve
< 42.8uA average current
drain
b. With smoke being detected
(measured with conditions
of both alarm on and alarm
off).
MikeC.(10Mar2014)
a. Standby current is a
little high at ~84uA
@VDD = 3.4Volts,
~69uA @VDD =
2.7Volts.
b. When alarm is
sounded the current
drain is 74mA @VDD =
3.4Volts (58.3mA
@VDD = 2.7V) and
~85uA (~69uA @VDD
= 2.7V) during 3second
Alarm OFF period
when smoke is
detected.