The type KS-501-F microprocessor controlled immission air / gas sampling measuring circuit is of portable design and, with application of the built-in gas wash vessels and/or sorption pipes, it is suitable for 8*24-hour sampling of practically all known gaseous air pollutants in automatic or manual operation modes. For determination of the gaseous pollutants found in the ambient air, adsorption and absorption sampling methods and measuring circuits serve. According to the known measuring principle, an air quantity measured with adequate accuracy and set to constant value is passed through a solution or sorbent adsorbing most efficiently the pollutant, then the samples are analysed by some analytical method.

The type KS-501-F eight-channel automatic air sampler entirely eliminates the inaccuracies of the gas and air samplers known to date originating from the volume flow rate measurement, as well as the deficiencies of the channel selector coming from the leaks of the channel selector device (what often can not be located), meanwhile suitable for multi-purpose sampling. The type KS-501-F air samplers are equipped with micro-intake Venturi meter individually calibrated in our laboratory with use of measuring devices attested by the National Office of Measures, Æ 50 [mm] solid material collecting filter, eight absorbing vessels, eight high-pressure Bosch magnetic valves, furthermore, with a vacuum pump producing high - Dpst=500 [mbar] – pressure difference.

The air – gas sampler illustrated in Figure 1. consists of the following main sub-units:

• The in-draught structure, with micro Venturi, airborne dust filter with holder box.

• Air manifold, supporting structure.

• Exhaustion arrester device.

• Absorbing vessels, two-way magnetic valves with connections and air ducts, with cables and electric fittings.

• Vacuum pump integrated with motor, with outblow device, connection cables, measuring and control electronics with foil-type keypad.

• Two-level, corrosion-proof supporting frame structure.

From the air flowing from the outer atmosphere through an in-draught device (Figure 1.) and a short diffuser pipe section, the airborne dust is intercepted by an Æ 50 [mm] flat filter. The air purified from the solid particles is passed through the absorbing fluid existing on the sampler vessel, the magnetic valves and the vacuum pump, via the exhaust pipe, to the outer atmosphere.

The volume flow measuring and evaluation unit, processing the electric signal proportional to the temperature and pressure of the in-draught air, the pressure signal of the in-draught Venturi meter as well as the loaded data, measures the quantity of the through-suctioned air [ lN/h ], the total volume [ l N ] through-suctioned during the sampling and, per channel, the duration of the sampling. In automatic mode of operation the instrument changes channel after every 24 hours, at midnight, and stores all of the measured data. The measured data can be printed in detailed breakdown – either per channel – with scrolling on the display, interconnected with a PC. In case of power supply failures no data loss occurs in the system. The magnetic valves prevent shorting of the channels and at the same time ensure the perfect and long-lasting tightness at the channel change. The detachable stuffing-box connections with input and output locking serve also for the perfect air-tightness. Stabilization of the mass flow at the set value is ensured by the microprocessor electronics. For the regular accuracy test a micro metering orifice attested by the National Office of Measures (OMH) and a digital pressure gauge are sufficient.

Each instrument produced by us is tested in our laboratory with use of attested measuring devices calibrated by the National Office of Measures and, the results are recorded in a protocol.

The KS-501-F air sampler is marketed with a calibration certificate issued by the Environment Protection Reference Center The entire sampling surface, the in-draught head, the micro-Venture, the filter box and the manifold are made of inert materials. Protection of the system against dust pollution is ensured by an adapter filter, whilst the vacuum pump is provided with a separate protection filter. The in-draught device is also provided with hidden openings and for this reason the back-draught originating from improper usage is practically impossible. As ultimate protection, fluid trap, collecting container can be found under the channel manifold housing. By means of the measuring and regulating unit of the KS-501-F instrument the mass flow and the sampling time can be adjusted over a wide range and the instrument can be operated in either manual or automatic mode.