Products: 

 Previous   Next 

In all types of industries, the people are exposed to many gases (toxic). To evaluate and control the exposure in terms of toxicity to a working station became paramount.

The apparatuses proposed make it possible to measure directly on site the concentrations of these gases and to calculate the exposure limit values thanks to different techniques:

• Photoionization (PID).

• The electrochemical cell.

• The acoustic photo spectroscopy.

A UV lamp generates photons which ionize the molecules whose potential of ionization is a inferior to the energy of the lamp.
The formed ions are collected by electrodes between which a potential difference is established. the ions move in the electric field and generate a current proportional to the concentration in ionized molecules.

Detection PID can only be used for the determination of the total COV or in partnership with columns of chromatography. This chromatograph portable gas makes it possible to identify and quantify the COV. This analyzer is ideal in the weak concentrations as of the ppb.

More than 200 COV are detectable by photoionization. Its principal applications are the depollution of the grounds, benzène detection, etc.

This cell from the last generation have, most of time, 2 or 3 electrodes bathing in an electrolyte. With gas, a current is established, proportional to the concentration. To allow the selectivity, the selected electrolyte is placed in a closed space separated of the medium to measure by a membrane. In all the types of industries, the electrochemical cells allow the protection of the personnel and the installations. The individual safety is ensured by portable apparatuses the transmitters posts fixes are declined in standard version or hazardous areas.

This technique is based on the capacity of gases to absorb the light infrared. but with the difference of the other analyzers IR, it is an acoustic signal which is measured using 2 membrane microphones, signal generated by gas by absorbing the light IR. The main advantages of this technique are excellent a stability and thresholds of detection of a few tens of ppb.