Test method for carbon monoxide in air (1)
Non-spectral infrared gas analysis
Carbon monoxide is a selective absorber of non-spectral infrared rays. Within a certain range, the absorption value is linearly related to the CO concentration. The concentration of carbon monoxide in the sample was determined according to the absorption value.
2. Reagents and materials
2.1 Color changing silica gel: dry at 120℃ for 2h.
2.2 Anhydrous calcium chloride: analytical pure.
2.3 High purity nitrogen: 99.99% purity.
2.4 Hopcalite oxidant: 10 ~ 20 mesh particles. The main components of Hogarat oxidant are oxide (MnO) and copper oxide (CuO). Its function is to oxidize carbon monoxide in the air to carbon dioxide, which is used for instrument zero adjustment. The oxidation efficiency of this oxidant should reach 100% under 100℃. In order to ensure its oxidation efficiency, it should be kept dry during use and storage.
2.5 Carbon monoxide standard gas: stored in aluminum alloy bottles.
3. Instruments and equipment
3.1 Carbon monoxide non-spectral infrared gas analyzer.
3.1.1 Main performance indicators of the instrument are as follows:
Measuring range: 0 ~ 30ppm; 0 ~ 100ppm two grades
Reproducibility: ≤0.5%(full scale)
Zero drift: ≤±2% full scale /4h
Span drift: ≤±2% full scale /4h
Linear deviation: ≤±1.5% full scale
Start time: 30min ~ 1h
Pumping flow: about 0.5L/min
Response time: pointer indication or digital display to full engraved 90%<15S 3.2 recorder 0 ~ 10mV