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Fomaldehydrade (HCHO)
Item Item Details
(Price is for domestic US market only)
Fomaldehydrade (HCHO)
Item Name:
Fomaldehydrade (HCHO)
Item #:

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Formaldehyde HCHO NO.91M



Measuring Range

8 to 20ppm

20 to 2000ppm

2000 to 6400ppm

Number of Pump Strokes




Correction Factor




Sampling Time

1.5 minutes per pump stroke

Detecting Limit

4 ppm (n=2)

Color Change

Yellow Red

Reaction Principle

H3PO4 + Base Phosphate

Coefficient of Variation 10% (for 8 to 200 ppm), 5% (for 500 to 2000 ppm)
Shelf Life 2 Years
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)




Change color by itself


5 times

Plus error

Produces red stain at 20 ppm


1/6 time

Plus error

Produces red stain at 3 ppm

Calibration gas generation Diffusion tube method

TLV-TWA TLV-STEL Explosive range
- C 0.3ppm 7.0 to 73%

Range 8-6400

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