|
|
| Hydrogen sulfide |
H2S |
NO.4D |
| Performance |
Measuring
Range
|
0.2 to 200 ppm |
Sampling Hours
|
1 to 48 hours |
Detecting Limit
|
0.2ppm (10 hours) |
Color Change
|
White ---> Brown |
| Reaction
Principle |
Hydrogen sulfide
react with lead acetate to
produce lead sulfide which color is brown.
H2S + Pb(CH3COO)2 ---> PbS + 2CH3COOH |
| Coefficient
of Variation |
10% (for 10 to
200 ppm-hr) |
| Shelf
Life |
3 Years |
| Corrections
for temperature & humidity |
Unnecessary |
| Store the
tubes at cool and dark place. |
| Possible
coexisting substances and their interferences |
Substance
|
Concentration
|
Interference |
Change
color by itself |
Nitrogen dioxide
|
5 ppm
|
Minus error
|
No discoloration
by itself |
Ammonia
|
25 ppm |
No effect
|
No discoloration
by itself |
| Chlorine |
1 ppm |
No effect |
No discoloration
by itself |
| Sulfur dioxide |
5 ppm |
No effect |
No discoloration
by itself |
| Calibration
gas generation |
Permeation tube method |
TLV-TWA
|
TLV-STEL
|
Explosive
range |
| 10ppm |
15ppm |
4.0 to 44% |
|
