TGS2442 Datasheet, PDF (11/25 Pages) List of Unclassifed Manufacturers – Detection of Carbon Monoxide

TECHNICAL INFORMATION FOR TGS2442
4-2 Long-term stability
Figure 16 shows long-term stability data for TGS2442.
Test samples were energized in normal air and under
standard circuit conditions. Measurement for
confirming sensor characteristics was conducted
under standard test conditions (20˚C, 65%RH). The
initial value was measured after four days of
energizing in normal air at the rated voltage. The Y-
axis shows the ratio between measured sensor
resistance and the initial (Day 4) resistance value,
each in 100ppm of CO. Additional data will be
published as it becomes available.
1000
100
10
1
0.1
0
Air
CO 30ppm
CO 100ppm
CO 300ppm
H2 1000ppm
EtOH 1000ppm
50 100 150 200 250 300 350
Time (days)
Figure 16 - Long term stability
(Ro = Rs in 100ppm of CO at Day 4)
4-3 Corrosion test
To demonstrate the durability of TGS2442 against
corrosion, samples were subjected to test conditions
called for by UL2034, Sec. 57-Corrosion Test. Over a
three week period, a mixture of 100ppb of H2S, 20ppb
of Cl2, and 200ppb of NO2 was supplied to the sensor
at a rate sufficient to achieve an air exchange of 5
times per hour. When compared to reference samples
not subjected to these corrosive gases, no significant
difference can be noticed.
4-4 Variable ambient temperature test
To show the ability of TGS2442 to withstand the
effects of high and low temperatures representative
of shipping and storage, the sensor was subjected to
the test conditions of UL2034 Sec. 44.2-Effect of
Shipping and Storage. Unenergized test samples
were subjected to 70˚C for 24 hours, allowed to cool
to room temperature for 1 hour, subjected to -40˚C
for 3 hours, and then allowed to warm up to room
temperature for 3 hours. When compared to
reference samples not subjected to these temperature
extremes, no significant difference can be noticed.
10
Test
1
CO 30ppm (ref)
CO 100ppm (ref)
CO 300ppm (ref)
CO 30ppm (test)
CO 100ppm (test)
CO 300ppm (test)
0.1
0
5 10 15 20 25 30 35 40
Time (days)
Figure 17 - Durability against corrosion
(Ro = Rs in 100ppm of CO at Day 2)
CO 30ppm (ref)
CO 100ppm (ref)
CO 300ppm (ref)
CO 30ppm (test)
CO 100ppm (test)
10
CO 300ppm (test)
Test
3 hrs. after test
1
0.
0
5
10
15
20
25
30
Time (days)
Figure 18 - Variable ambient temperature test
(Ro = Rs in 100ppm of CO at Day 0)
Revised 03/00
9