Drager tubes

Table 10.18(b) Drager tubes for long-term measurements - with pump... 

Drager tube Range of measurement for maximum period of use... 

Drager tubes for short-term measurements DrSger tube Range of measurement (2(fC, 1013 mbar)... 

In the full scale fire tests some additional gaseous species were studied specifically, i.e. formaldehyde. Not all gas species were studied in every test. Hydrogen cyanide and hydrogen chloride have only been studied in situations where evolution of these species were suspected. HCN and HC1 have only been studied as collective (2, 5 or 10 minutes) samples for each fire test. It is most preferable to follow the concentrations with direct reading instruments. This has been the case for carbon monoxide, carbon dioxide, oxygen and in three out of four cases for nitrous oxide. Drager tubes were used for measurements of nitrous oxides in the DIN 53436 test. 

Hydrogen cyanides have been investigated using Drager tube only. Thus the results are only qualitative. 

There should be no measured speed at any point from the bottom to the top (anemometer). No opposite flow should be visualized with the Drager tube and pump. It is preferable that left to right speed variation be lower than 30% around the mean. The number of points out of this limit is to be minimized. 

Hydrogen sulfide emissions were monitored at the sulfur-asphalt mixing equipment at the hot-mix plant and at the paving site. A Houston-Atlas ambient H2S detection system, furnished and operated by the U.S. Bureau of Mines, was used as well as portable equipment such as a Rotorod Gas Sampler and Drager tubes. The emissions at some of the critical areas of the hot-mix plant and paving site are given in Table VI. 

Drager tubes for short-term measurements Drager tube... 

Drager tubes for long-term measurements Drager tube Range of measurement in absolute units (20°C, 1013 mharl Range of measurement for maximum period of use... 

On-line analysis of the effluent gases was conducted using a gas chromatograph (Hewlett Packard model 5890 Series H), equipped with FID and TCD detectors. A DB-624 fused silica capillary column was used for the hydrocarbon separation. The carbon monoxide and carbon dioxide were separated using molecular sieves (5A) and Hayesep R columns. Tlie effluent gases were analyzed for the unconverted VOCs, partial oxidation products such as chloroform and 1,1,2-trichlorocthanc, and total oxidation products (CO and COj). The HO and Clj analysis was performed using Drager tubes. The total conversion is based on total cartoon atoms in the feed. 

Drager Ltd (1997) Drager Tube Handbook. Dragerwerk AG, Liibeck, Germany. 

Drager-Tube Handbook, Drager Sicherheitstechnik GmbH, Ltibeck,... 

To measure sulfur losses, check for H2S and SO2 in the final condenser effluent. Drager tubes are a simple and reasonably accurate way to get this data. Don t submit sulfur plant tail gas samples to the lab for analysis. The H2S and SO2 will react in the sample container to form solid sulfur and water. To calculate conversion from these measurements ... 

Theoretically, the increase of sulfur vapors to the first reactor would reduce conversion. In practice, a small shift in the reactor temperature rise from the lead reactor to the second and third reactors was noted. The theoretical reduction in conversion was too small to observe with a Drager tube analysis of the sulfur plant tail gas. 

Carbon monoxide Internal combustion engine 0-02% headache in 5-6 h 0-50-1% death in 2-15 min 0 0005% (the body can accumulate carbon monoxide Drager tubes... 

Hydrogen sulphide Rotting vegetation 0-05% poisonous 0-10% causes serious symptoms Any trace Drager tubes (ppm)... 

Petrol fumes Fuel on site Explosion, fire 0-3% Drager tubes... 

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