| Benzene | C6H6 | NO.121SP | |
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| Performance |
|
Measuring Range |
0.5 to 10 ppm |
|
Number of Pump Strokes |
3 |
|
Correction Factor |
1 |
|
Sampling Time |
1.5 minutes per pump stroke |
|
Detecting Limit |
0.2 ppm (n=3) |
|
Color Change |
White |
|
Reaction Principle |
Benzene reacts with formaldehyde to form a condensation polymer, which is brown stain. 2C6H6+ HCHO |
| Coefficient of Variation | 10% (for 0.5 to 3 ppm), 5% (for 3 to 10 ppm) |
| Shelf Life | 2 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 color by itself |
|
Hexane |
500 ppm |
No effect |
No discoloration |
|
Toluene |
100 ppm |
No effect |
No discoloration |
|
Xylene |
100 ppm |
No effect |
No discoloration |
|
Aromatic hydrocarbons other than benzene are trapped in the brown layer in the pretreatment tube.If the pretreatment reagent is entirely consumed (whole brown layer turns to dark brown),a higher reading will be given. |
| Calibration gas generation | Diffusion tube method | |
| TLV-TWA | TLV-STEL | Explosive range |
| 0.5ppm | 2.5ppm | 1.3 to 7.1% |
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| Copyright(c) 2001 GASTEC CORPORATION. All rights reserved. |
Brown
C6H5CH2C6H5 + H2O
Reaction product