|
|
| Performance |
Measuring
Range
|
100 to 25000 ppm |
Sampling Hours
|
1 to 10 hours |
Detecting Limit
|
0.05 ppm (10 hours) |
Color Change
|
Yellow --->
Brown |
| Reaction
Principle |
Ethanol reduces
cromic acid to discolor brown stain.
C2H5OH + Cr6++ H2SO4 ---> Cr3+ |
| Coefficient
of Variation |
15% (for 1000 to
3000 ppm-hr), 10% (for 3000 to 25000 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 |
Methanol,Esters
|
-
|
No effect
|
No discoloration |
Isopropyl alcohol
|
1time
|
Plus error
|
Discolor brown |
| Calibration
gas generation |
Permeation tube method |
TLV-TWA
|
TLV-STEL
|
Explosive
range |
| 1000ppm |
- |
3.3 to 19% |
|
