Formaldehyde 0.2/a, 0.5 - 5 PPM, Part # 6733081, 10 Tests 

Application Range

Standard Measuring Range: 0.5 to 5 / 0.2 to 2.5 ppm

Number of Strokes n: 10 / 20

Time for Measurement: approx. 1.5 min / approx. 3 min

Standard Deviation: ± 20 to 30 %

Color Change: white š pink

Ambient Operating Conditions

Temperature: 10 to 40 °C

Absolute Humidity: 3 to 15 mg/ L

Reaction Principle

HCHO + C6H4(CH3)2 + H2SO4 š quinoid reaction products

Cross Sensitivity

Styrene, vinyl acetate, acetaldehyde, acrolein, diesel fuel and furfuryl alcohol are indicated with a yellowish brown discoloration. 500 ppm octane, 5 ppm nitric oxide and 5 ppm nitrogen dioxide have no effect.

Extension of the Measuring Range

The measuring range can be extended in conjunction with the activation tube (Order No. 81 01 141). The following information applies to the n = 20 stroke scale:

Pump Strokes                                 Scale divided by                        Range

40                                                          2                                   0.1 to 1.25 ppm

80                                                          4                                  0.05 to 0.63 ppm

100                                                        5                                  0.04 to 0.5 ppm