ECOPROBE 5 - rs dynamics
ECOPROBE 5 - rs dynamics
ECOPROBE 5 - rs dynamics
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PID ANALYZER<br />
Diesel and gasoline fuels are the most common contaminants encountered in a soil vapor survey. The Table<br />
of measured compounds also offe<strong>rs</strong> data for the most generally occurring petroleum fuels such as Diesel fuel<br />
#1, Diesel fuel #2, Gasoline #1, Gasoline #2, Jet fuel JP-4, Jet fuel JP-5, Jet Fuel JP-8. Selecting the most<br />
suitable mixture enables you to get results which are close to quantitative values.<br />
<strong>ECOPROBE</strong> 5 is equipped with 10.6 eV ionization lamp. Other lamps are optional and may be ordered from<br />
the manufacturer. All lamps feature selective methane suppression.<br />
The table is valid only for a PID analyzer and has no connection with the IR analyzer. IR analyzer<br />
operates on a different principle.<br />
<strong>ECOPROBE</strong> 5‘s PID ANALYZER CHARACTERISTICS<br />
• Detection limit: 0.1 ppm for STANDARD mode; low ppb values for HISENS mode.<br />
• Calibration for quantitative vapor phase determination for over 200 compounds.<br />
Zero response for methane which is measured separately by the IR unit.<br />
• Large dynamic range (low ppb to 4000 ppm), fast response (0.5 sec).<br />
• Ion lamp 10.6 eV (other energy levels are optional).<br />
• STANDARD mode with ppm or mg/m3 output or HISENS mode with ppb or µg/m3 output.<br />
PHOTO- IONISATION BREAKDOWN (QUENCHING)<br />
Generally, the photo-ionisation process has physical limitations. For a concentration higher than a certain<br />
value the ionization process will breakdown. Further increase of concentration may even lead to a diminished<br />
output. The average value of photo-ionisation breakdown limit is around 4 000 ppm but it varies for different<br />
spectral compounds.<br />
To indicate this phenomenon by means of operating software is not usually possible and is not available for<br />
PID instruments on the market.<br />
<strong>ECOPROBE</strong> 5 indicates a concentration level that exceeds the photo-ionisation breakdown limit, mainly by<br />
a low “breakdown” value (hundreds of ppm). It may also display the message “over” on the instrument<br />
screen. The mode in which the breakdown is announced depends on various facto<strong>rs</strong> such as particular<br />
compounds, the speed of the breakdown process, concentration level, etc. All these paramete<strong>rs</strong>, which are<br />
valid for the STANDARD mode only, should be considered in the interpretation.<br />
The graph in Fig.21 illustrates the position of the highest contamination on a survey line, in the interval from 8<br />
to 14 m (metres) , where message “over” was displayed.<br />
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