| H2S |
 |
Performance
| Measuring Range |
| 25 to 50 ppm |
50 to 800 ppm |
800 to 1600 ppm |
|
| Number of Pump Strokes |
|
| Correction Factor |
|
| Sampling Time |
1 minute per pump stroke |
| Detecting Limit |
5 ppm (n=2) |
| Colour Change |
White → Brown |
| Reaction Principle |
H2S + Pb(CH3COO)2 → PbS + 2CH3COOH |
| Coefficient of Variation |
5% (for 50 to 800 ppm) |
| Shelf Life |
3 Years |
| Corrections for temperature & humidity |
Unnecessary |
| Store the tubes at cool and dark place. |
Possible coexisting substances and their interferences
(NOTE)
| Substance |
Concentration |
Interference |
Change colour by itself to |
Other substance measurable with this detector tube
| Substance |
Correction Factor |
No. of pump strokes |
Measuring Range |
| Nitrogen dioxide |
1/4 time |
|
No |
| sulphur dioxide |
1/1 |
+ |
No |
| Ammonia |
|
No |
No |
| Carbon dioxide |
|
No |
No |
| Carbon monoxide |
|
No |
No |
| Mercaptans |
|
No |
No |
| Organic gases & vapours |
|
No |
No |
| Calibration gas generation |
Permeation tube method |
| TLV-TWA |
TLV-STEL |
Explosive range |
| 10 ppm |
15 ppm |
4.0 to 44% |
