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| EDENVIS |
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HIGH LEVEL EDUCATION IN ENVIRONMENTAL SCIENCES |
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| Real Time Air Pollution Monitoring Simulators (block diagram) |
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| Characteristics of SnO2 Semiconductor Sensors |
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Items |
TGS 822 |
TGS 831 |
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Target gas |
Alcohol |
Freons R21, R22 |
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Typical detection range |
50 - 5000 ppm |
100 - 3000 ppm |
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Conditioning period |
> 7 days |
> 7 days |
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Sym. |
Cond. |
Specs. |
Cond. |
Specs. |
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Sensor resistance |
Rs |
Ethanol
at 300 ppm |
1 - 10 kΩ |
R22
at 1000 ppm |
1 - 10 kΩ |
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Sensitivity |
Rs/R0 |
Rs ( 300 ppm)
/ Rs (50 ppm) |
0.4 ± 0.1 |
Rs ( 1000 ppm)
/ Rs (300 ppm) |
0.4 - 0.15 |
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Load resistance |
RL |
Min 450 Ω |
Variable |
Min 450 Ω |
Variable |
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Circuit voltage |
VC |
DC only
Ps ≤ 15 mW |
Max. 24 V |
DC only
Ps ≤ 15 mW |
Max. 24 V |
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Heater voltage |
VH |
AC or DC |
5 ± 0.2 V |
AC or DC |
5 ± 0.2 V |
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Heater resistance |
RH |
Room temp. |
38 ± 3 Ω |
Room temp. |
30 ± 3 Ω |
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Heater power consumption |
PH |
VH = 5 V |
660 mW
(typical) |
VH = 5 V |
835 mW
(typical) |
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Items |
TGS 842 |
TGS2600 |
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Target gas |
Methane |
Carbon monoxide |
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Typical detection range |
500 - 10000 ppm |
30 - 100 ppm |
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Conditioning period |
> 7 days |
> 7 days |
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Sym. |
Cond |
Specs. |
Cond |
Specs. |
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Sensor resistance |
Rs |
Methane
at 1000 ppm |
3 - 15 kΩ |
Clean air |
10 - 90 kΩ |
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Sensitivity |
Rs/R0 |
Rs ( 3000 ppm)
/ Rs (1000 ppm) |
0.55 ± 0.05 |
Rs ( 100 ppm)
/ Rs (air) |
0.3 - 0.6 |
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Load resistance |
RL |
Min 450 Ω |
Variable |
Ps ≤ 15 mW |
Variable |
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Circuit voltage |
VC |
DC only
Ps ≤ 15 mW |
Max. 24 V |
Ps ≤ 15 mW |
5.0±0.2 V DC |
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Heater voltage |
VH |
AC or DC |
5 ± 0.2 V |
AC or DC |
5.0±0.2 V DC |
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Heater resistance |
RH |
Room temp. |
30 ± 3 Ω |
Room temp. |
83 Ω |
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Heater power consumption |
PH |
VH = 5 V |
835 mW
(typical) |
VH = 5 V |
210 mW |
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| Signal conditioning circuit |
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