Vạch chỉ thị: 0.2 ~ 20 ppm
Thang đo:
+ 0.2 ~ 20 ppm, bơm 3 lần
+ 20 ~ 66 ppm, bơm 1 lần
Thời gian lấy mẫu: 2 phút mỗi lần bơm
Chuyển đổi màu: Trắng sang nâu
Phương trình phản ứng: 2C6H6+ HCHO → C6H5CH2C6H5 + H2O, C6H5CH2C6H5 + H2S2O7 → Condensation polymer
Hệ số biến đổi: 10% (0.2 ~ 5ppm) , 5% (5 ~ 20 ppm)
Số ống trong hộp: 5
Dùng thích hợp với bơm: GV-100S/110S
Catalog
Manual
Performance
| Measuring Range |
0.2 to 20 ppm |
20 to 66 ppm |
| Number of Pump Strokes |
3 |
1 |
| Correction Factor |
1 |
3.3 |
| Sampling Time |
2 minutes per pump stroke |
| Detecting Limit |
0.1 ppm (n=3) |
| Colour Change |
White → Brown |
| Reaction Principle |
2C6H6+ HCHO → C6H5CH2C6H5 + H2O C6H5CH2C6H5 + H2S2O7 → Condensation polymer |
| Coefficient of Variation |
10% (for 0.2 to 5ppm) , 5% (for 5 to 20 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 colour by itself to |
| Hexane |
≦ 500 ppm |
No |
No |
| Toluene |
≦ 300 ppm |
No |
No |
| Xylene |
≦ 350 ppm |
No |
No |
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 |
| 0.5 ppm |
2.5 ppm |
1.3 to 7.1% |