甲醛氣體檢知管91LL Formaldehyde 的詳細(xì)介紹
 甲醛氣體檢知管91LL Formaldehyde
Formaldehyde           No.91LLHCHO
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 → Reddish Brown
Reaction Principle
3HCHO + (NH2OH)3H3PO4 → H3PO4
H3PO4 + Base → Phosphate
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
(Unclear demarcation)
Faint reddish brown to whole layer
Ketones
1:1
Plus error
(Unclear demarcation)
Faint reddish brown to whole layer
Toluene
10ppm
No effect
No discoloration