Acetaldehyde CH3CHO No.92L

3CH3CHO ＋（NH2OH）3･H3PO4 → H3PO4

H3PO4 ＋ Base → Phosphate

Reaction principle

Diffusion tube methodCalibration gas generation

0.2 ppm（1 pump stroke）Yellow → Reddish brownTemperature 5 to 40 ℃ (41 to 104 ℉) correction used Relative humidity 20 to 90 % correction not used10 %（for 1 to 6 ppm）, 5 %（for 6 to 20 ppm）10 tubes for 10 tests24 months（in the refrigerator）

Detecting limit :Colour change :Operating conditions :

Relative standard deviation :Tube quantity and number of tests per box :Shelf life :

Performance

1 to 20 ppm 1（100 mL） 1 2 min

Measuring rangeNumber of pump strokesCorrection factorSampling time

Possible coexisting substances and their interferences

Ammonia ≦ 30ppm No No Acetic acid ≧ 2 times ＋ Reddish brownAcids ＋ Reddish brownAldehydes ＋ Reddish brownKetones ＋ Reddish brown

Substance Concentration Interference Changes colour by itself to

1 2 4 6 8 10 12 14 16 18 20 ppm

n=1

92LScale