Hygitest Detection Tubes (Air Contaminants)

Hygitest Colorimetric Tubes
(For Short-Term Analysis of Air Contaminants)

The Hygitest indicator tubes are used for express determination of toxic gases and vapours concentrations in industrial environment. The analyses are quick, easy to perform and unexpensive. No special training is required for the operating staff. For this reason the indicator tubes are widely used in all branches of industry, agriculture, transport, etc. They are used for apparatus leakage determination, control of technological processes and determination of toxic substances in the environmental air, for hygienic evaluation, testing the presence of toxic and inflammable substances in confined spaces, determination of workers personal exposure, determination of gas components in liquids, etc. A feature worth mentioning is that the data on the substance are determined instantly on the spot.

The HYGITEST indicators are glass tubes, filled with solid granular material-carrier, impregnated with an appropriate chemical reagent. The tips of the tube are sealed, thus its content is isolated from the environment. Before analysis, the tips of the tube are broken and the tube is inserted in the special sampling pump, HYGITEST or DRAEGER type, sucking the air quantity necessary for each kind of tube.

In the presence of the substance to-be-analysed, the reagent system in the tube changes its colour and the length of the discoloration is directly proportional to the concentration of the substance determined. The concentration is read directly on the scale, printed on the outside surface of the indicator tube.

All data necessary for reproduction of analysis and obtaining of precise results are presented in the detailed operating instruction, enclosed in each package of indicator tubes.

Analysis indicator tubes are intended for instant “on-the-spot”determination of the concentration of toxic substances in the air. Depending on the concentration range they can be used for determination of toxic substances in the working medium, in the atmospheric air and also in emissions. Sampling with them does not exceed 10 minutes, usually within 3 to 5 minutes. For the purpose they are precisely calibrated so that the determination error does not exceed the (+ -- ) 25% limit admissible in hygienic practice. The reproducibility of the indications of the tubes from one batch, expressed by a coefficient of variation, is usually within the range 10 to 15%, depending on the tube type and the skill of the operator. Indicator tubes, with indications affected by the humidity of analysed air are calibrated with dynamic dosage apparatuses with controlled airflow hymidity. Calibration curves for each humidity value are obtained from 3 to 16 d/m3, but a scale valid at 9 d/m3 (50% relative humidity at 20gr C/ is usually printed on the tube. The results from the analyses under other humidity conditions are multiplied by correction coefficients, given in the instruction, in each package of indicator tubes. A large number of the humidity-affected indicator tubes is already being supplied with a drying filter layer, eliminating the necessity of correction coefficients.

The analysis with the indicator tubes is realised by means of special sampling pumps. HYGITEST analysis tubes are calibrated with two types of pumps: DRAEGER bellows pump widely used in the world practice and BPP-2M piston pump produced by HYGITEST. The results, obtained by the two types of pumps, coincide in the majority of cases. In case of lack of coincidence this is mentioned in the instructions.


List of Hygitest Detection Tubes for Air Contaminants