| Formaldehyde | HCHO | NO.91LL | |
|
|
|||
| Performance |
|
Measuring Range |
0.05 to 1.0 ppm |
|
Number of Pump Strokes |
5 |
|
Correction Factor |
1 |
|
Sampling Time |
1.5 minutes per pump stroke |
|
Detecting Limit |
0.03 ppm (n=5) |
|
Color Change |
Yellowish Brown |
|
Reaction Principle |
3HCHO + (NH2OH)3H3PO4 |
| Coefficient of Variation | 10% (for 0.05 to 0.3 ppm), 5% (for 0.5 to 1.0 ppm) |
| Shelf Life | 1 Year |
| Corrections for temperature & humidity |
Temperature correction is necessary |
| Store the tubes in the refrigerator to keep at 10oC (50oF) or below. | |
| Possible coexisting substances and their interferences | (NOTE) |
|
Substance |
Concentration |
Interference |
Change color by itself |
|
Ammonia |
- |
Minus error |
Faint dull yellow color to whole layer |
|
Nitrogen dioxide |
- |
No effect |
Pale pink discoloration around zero |
|
Aldehydes |
1/3 time |
Plus error |
Faint reddish brown to whole layer |
|
Ketones |
1:1 |
Plus error |
Faint reddish brown to whole layer |
|
Toluene |
10ppm |
No effect |
No discoloration |
| Calibration gas generation | Diffusion tube method | |
| TLV-TWA | TLV-STEL | Explosive range |
| - | C 0.3ppm | 7.0 to 73% |
|
|
| Copyright(c) 2001 GASTEC CORPORATION. All rights reserved. |
Reddish Brown
H3PO4
Phosphate