|
|
| Hydrogen cyanide |
HCN |
NO.12D |
| Performance |
Measuring
Range
|
1 to 200 ppm |
Sampling Hours
|
1 to 10 hours |
Detecting Limit
|
0.04 ppm (10 hours) |
Color Change
|
Yellow --->
Red |
| Reaction
Principle |
Hydrogen cyanide
react with mercury
chlorideto discolor the indicator to red. |
| Coefficient
of Variation |
10% (for 10 to
200 ppm-hr) |
| Shelf
Life |
3 Years |
| Corrections
for temperature & humidity |
Humidity correction
is necessary |
| Store the
tubes at cool and dark place. |
| Possible
coexisting substances and their interferences |
Substance
|
Concentration
|
Interference |
Change
color by itself |
Ammonia
|
-
|
Minus error
|
No discoloration |
Nitrogen dioxide
|
-
|
Plus error
|
Produce reddish
stain |
Hydrogen sulfide
|
-
|
Plus error |
Produce reddish
stain |
Amines
|
- |
Minus error |
No discoloration |
| Calibration
gas generation |
Permeation tube method |
TLV-TWA
|
TLV-STEL
|
Explosive
range |
| - |
C 4.7 ppm |
5.6 to 40% |
|
