1. General:
Ionization smoke chamber NIS-02A is a newly developed smoke sensor to detect
only smoke generated in the event of fire, cigarette smoke and dust. This sensor
is a low radioactivity version of our standard smoke sensor NIS-09C, and is not
restricted as a radioisotope described in the international advice. Furthermore,
the radioactive source is completely sealed as same as NIS-09C, then it can be
handled as an electronic part.
The following are features of NIS-02A.
1) Features;
* The extremely small power consumption enables to operation by battery for
several years.
* Simple structure and less expensive than photo-electric type smoke sensors.
* Output is not dependent on colors of smoke.
* Superior durability to photo-electric type smoke sensors.
* Lowest radioactivity less than international restriction on radioisotope.
2) Applications;
* Fire alarms * Air purifiers * Dust counters
3) Maximum ratings;
* Supply voltage DC 24V
* Temp. & humidity in operation Temperature -20 ?+70 degree C
Humidity Less than 95% RH
* Temp. & humidity in storage Temperature -25 ?+80 degree C
Humidity Less than 95% RH
4) Recommended ratings;
* Supply voltage DC 9V
* Current consumption 7 +/- 2 pA (When 9V is supplied)
* Output in clean air 6.0 +/-0.5 V (25 degree C, 60% RH)
* Smoke sensitivity 1.1 +/- 0.3 V (2%/foot, according to UL217)
* Temp. & humidity in operation Temperature -10 ?+60 degree C
Humidity Less than 95% RH
* Temp. & humidity in storage Temperature -10 ?+70 degree C
Humidity Less than 95% RH
5) Structure, dimensions, & weight
* Structure As per drawing on next page.
* Dimensions As per drawing on next page.
* Weight Approx. 13.7g
2
2. Structure
The following is the structure of NIS－02A
02A
7 .4
5±1
40±1
A
-
KB q
N I
O OT MEN
4 1 2 -
mA
S
1 3 . 5
2 0
60 . 0 ?
6 0 . 0 ?
φ30
1 7 φ44
V I E W . A
H
G
F
C
E
A
D
B
H Label (Aluminum sheet)
G Cover SUS304
F Lead wire Teflon
covered wire
E Potential
electrode
SUS304
D Inner
electrode A
SUS304
C Radiation
source
2 4 1Am
7.4KBq
B Inner plate SUS304
A Base mount PBT resin
No Parts Materials
Fig. 1 Structure of NIS－ 02A
Radioisotope mark is not specified on the actual label. The
radioisotope (C in the drawing) is Alpha ray emitting 241Am
(Americium-241) which radioactivity is as tiny as 7.4 KBq. As the
radioactive source is completely sealed by a stainless steel cover (G
in the drawing), radioactivity is not leaked to ambient environment.
The radioisotope itself is also completely sealed with gold plating
for corrosion resistance to organic solvents and acids. In addition
the mount base is also solvent resistant, therefore, chambers can
be washed with organic solvents when necessary. NIS-02A is a 1
source/2 chamber type and the mount base is made of a poly3