Hydrogen Sulfide,Sulfur Dioxide H2S,SO2
(Separete quantification)		 NO.45S
45S


Performance

Name of Gas

 SO2 tube H2S tube SO2 tube

H2S tube

 SO2 tube

H2S tube

Measuring Range

2.5 to 0.5

 12.5 to 2.5

0.5 to 10

 (2.5) to 60

10 to 20

 60 to 120

Pump Strokes

2

1

1/2

Correction Factor

1/2

1

 2

Sampling Time

1 minute per pump stroke

Detecting Limit

0.05 ppm (n=2)

Color Change

SO2 tube : Yellowish green Yellow
H2S tube : White Dark brown
Reaction Formula

SO2 tube:Sulfur dioxide reacts with barium chloride to liberate
hydrogen chloride to discolor the pH indicator to yellow.

H2S tube:Hydrogen sulfide reacts with lead acetate
to form lead sulfide, which color is brown.
Coefficient of Variation

SO2 tube: 10% (for 0.5 to 2 ppm), 5% (for 2 to 10 ppm)
H2S tube:10% (for 2.5 to 10 ppm), 5% (for 10 to 60 ppm)
Shelf Life 3 Years
Corrections for
temperature & humidity		 Unnecessary
Store the tubes at cool and dark place.


Possible coexisting substances and their interferences (NOTE)

Substance

Concentration

Interference

Change color by itself
SO2 tube H2S tube SO2 tube H2S tube

Nitrogen dioxide

 5 ppm Plus error No effect

Pale purple

 No discoloration

Nitrogen monoxide
Mercaptans
Carabon monoxide

 - No effect No effect No discoloration


Calibration gas generation Permeation tube method


TLV-TWA TLV-STEL Explosive range
SO2 : 2ppm
H2S : 10ppm		 SO2 : 5ppm
H2S : 15ppm		 H2S : 4.0 to 44%

Copyright(c) 2001 GASTEC CORPORATION. All rights reserved.