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Gastec Passive Dosi-Tubes

Gastec Colour Dosimeter Tubes (Dosi-tubes) provide reliable, on-the-spot Time-Weighted Average (TWA) monitoring of worker exposure to gases and vapours. The system is simple-to-use and easy-to-read, with no need for a pump, chart, or laboratory analysis. The Dosi-tube system allows an operator to evaluate the level of exposure over a long time period such as a working shift.

The system consists of Gastec Dosi-tubes and a tube holder (part number 810-710). The pre-scored ends of the tube are simply snapped off and the tube inserted into a tube holder. Air diffuses passively through the tube and reacts with the detecting reagent within, giving a colour change result that is indicated on the printed scale. The tube holder can either be attached in a worker’s breathing zone or installed in work areas to act as an area monitor.

Gastec Dosi-Tubes
Dosi-Tube Holder
Dosi-Tube Holder and Tubes

Using a simple equation, the Dosi-tube system produces an average concentration of exposure over a set period of time – commonly known as a Time Weighted Average (TWA). To calculate the ppm level simply read the printed calibrated scale on the tube for exposure measurement in parts-per-million-hours (ppm-hours), and divide the reading by the number of hours sampled.

Note: When measuring carbon dioxide, mount the tube holder on the worker’s waist rather than in their breathing zone. This will avoid overstating CO2 levels due to exhalation.

Dosi-Tube Holder
Description Pack Size Part Number  
Dosi-Tube Holder 3 810-710   810-710 Gastec Dosi-Tube Holder, which can either be attached in a worker’s breathing zone or installed in work areas to act as an area monitor. Air diffuses passively through the tube and reacts with the detecting reagent within, giving a colour change result that is indicated on the printed scale.  
Gastec Dosi-Tube Holder

810-710

Dosi-Tubes

Click on the part number to view the specific datasheet.

Chemical Tube Name Target Measuring Range (ppm) Sample Time (hours) Part Number
Acetaldehyde

CH3CHO
Formaldehyde 0.1-20 1-10 810-91D   *  
Acetone 4-1200 1-10 810-151D   *  
Methyl ethyl
ketone
1.2-360 1-10 810-152D   *  
Acetic acid

CH3CO2H
Acetic acid 0.5-100 1-10 810-81D
Acetic anhydride

(CH3CO)2O
Acetic acid 0.3-60 1-10 810-81D
Acetone

CH3COCH3
Acetone 1-1500 1-10 810-151D   *  
Methyl ethyl
ketone
1.4-420 1-10 810-152D   *  
Ammonia

NH3
Ammonia 2.5-1000 0.5-10 810-3D
Ammonia 0.1-10 1-10 810-3DL
Benzene

C6H6
Toluene 2.4-600 1-10 810-122DL
1,3-Butadiene

CH2:CHCH:CH2
1,3-Butadiene 1.3-200 1-8 810-174D
Carbon dioxide

CO2
Carbon dioxide 0.02-12% 0.5-10 810-2D
Carbon monoxide

CO
Carbon monoxide 1.04-2000 0.5-48 810-1D
Carbon monoxide 0.4-400 0.5-24 810-1DL   *  
Chlorine

Cl2
Chlorine 0.08-100 0.5-24 810-8D
Trichloroethylene 2.4-240 1-8 810-132D   *  
Cumene

C6H5CH(CH3)2
Toluene 3.4-850 1-10 810-122DL
1,2-Dichloroethylene

ClCH:CHCl
1,3-Butadiene 3.8-600 1-8 810-174D
Trichloroethylene 6-600 1-8 810-132D   *  
Dimethylamine

(CH3)2NH
Ammonia 1.9-750 0.5-10 810-3D
Ammonia 0.29-29 1-10 810-3DL
N,N-Dimethylethylamine

C2H5N(CH3)2
Ammonia 4-1600 0.5-10 810-3D
Ethanol

C2H5OH
Ethanol 100-25000 1-10 810-112D
Ethyl benzene

C6H5C2H5
Toluene 2.8-700 1-10 810-122DL
Ethylene

CH2:CH2
1,3-Butadiene 1.5-240 1-8 810-174D
Formaldehyde

HCHO
Formaldehyde 0.1-20 1-10 810-91D   *  
Formic acid

HCO2H
Acetic acid 0.55-110 1-10 810-81D
Furfural

C5H4O2
Formaldehyde 0.3-60 1-10 810-91D   *  
Hydrazine

N2H4
Ammonia 1.6-650 0.5-10 810-3D
Hydrogen chloride

HCl
Hydrogen chloride 1-100 1-10 810-14D
Trichloroethylene 1.8-180 1-8 810-132D   *  
Hydrogen cyanide

HCN
Hydrogen cyanide 1-200 1-10 810-12D
Hydrogen fluoride

HF
Hydrogen fluoride 1-100 1-10 810-17D
Hydrogen chloride 2.5-250 1-10 810-14D
Hydrogen peroxide

H2O2
Hydrogen peroxide 0.5-40 1-10 810-32D
Hydrogen sulphide

H2S
Hydrogen sulphide 0.2-200 1-48 810-4D
Isoprene

CH2:C(CH3)CH:CH2
1,3-Butadiene 2.6-400 1-8 810-174D
Methylamine

CH3NH2
Ammonia 0.19-19 1-10 810-3DL
Methyl ethyl ketone

CH3COC2H5
Methyl ethyl
ketone
2-600 1-10 810-152D   *  
Formaldehyde 0.125-25 1-10 810-91D   *  
Acetone 6.5-1950 1-10 810-151D   *  
Methyl isobutyl ketone

(CH3)2CHCH2COCH3
Acetone 11.5-3450 1-10 810-151D   *  
Methyl ethyl
ketone
4-1200 1-10 810-152D   *  
Nitric acid

HNO3
Hydrogen chloride 0.8-80 1-10 810-14D
Hydrogen chloride 0.32-32 1-10 810-17D
Nitrogen dioxide

NO2
Nitrogen dioxide 0.1-30 1-10 810-9D   *  
Nitrogen dioxide 0.01-3.0 1-24 810-9DL   *  
Styrene

C6H5CH:CH2
Toluene 26-6500 1-10 810-122DL
Sulphur dioxide

SO2
Sulphur dioxide 10-600 1-5 810-5DH
Sulphur dioxide 0.2-100 1-10 810-5D
Tetrachloroethylene

Cl2C:CCl2
Tetrachloroethylene 3-150 1-8 810-133D   *  
Trichloroethylene 1.5-150 1-8 810-132D   *  
Toluene

C6H5CH3
Toluene 2-500 1-10 810-122DL
Trichloroethylene

Cl2C:CHCl
Trichloroethylene 3-300 1-8 810-132D   *  
Triethylamine

(C2H5)3N
Ammonia 5.3-2100 0.5-10 810-3D
Trimethylamine

(CH3)3N
Ammonia 0.23-23 1-10 810-3DL
Vinyl chloride

CH2:CHCl
1,3-Butadiene 1.56-240 1-8 810-174D
Xylene

C6H4(CH3)2
Toluene 3.4-850 1-10 810-122DL

* Refrigerated storage - tubes to be stored at ≤10°C

Gastec Detector Tube List
Gastec Detector Tube List

Gastec Detector Tube List