Analyzer for measuring, small HCl concentrations in air (using a multipass cell), The AC 2.0 analyzer is finalized to the continuous monitoring of atmospheric HCl in a 1÷1000 ppb interval. This instrument finds its natural application in the surrounding of waste incinerators, or those other industries listing HCl among their raw materials, byproducts, or exhausts.
The instrument is based on the measurement of the
HCl molecules absorption of the instrument's
laser light emitted by the instrument's diode.
The concentration is obtained through the
measurement of the laser beam attenuation. This
particular method guarantees the total absence of
any interference from other atmospheric
constituent.
The surveying process adopts the double tone
frequency modulation technique. This technique
allows an efficient reduction of the measurement
noise.
The system is wholly controlled with an internal
CPU. The CPU manages the measurements, and
analyzes and transmits data.
The system is provided with two absorption cells.
Through the main one-an Herriot type cell with an
equivalent length of 28.3 meters-flows an air
stream at a pressure of 0.14 atm. A mix of HCl at
5% and Argon, is sealed in the second, 20 meters
long, cell. This second cell is used to hook up
the laser frequency.
The system's electronics includes a computer in
charge of operating the entire apparatus, data
analysis, and output organization.
The analyzer is made of three main components:
optical bench, electronics, and pump.
Technical data
- Multipass cell : Herriott type, 66 transitions, effective length 28.3 m, transmission 30%
- Survey: double tone frequency modulation, measurement frequency 8 MHz.
- Minimum threshold absorbance: 5·10-6
- Air stream: 1 lt STP/minute @ 0.14 atm
- CPU: DX 100 MHz
- Operating temperature: 0±40 °C (this interval can vary, depending on the laser characteristics)
- RS-232
Performances
| Concentration Interval | 2÷1000 ppb |
| Presentazione della lettura: | 2.5 Hz acquisizione singola, media semplice o rotante |
| Output | Voltage (0÷10 V) Current (4÷20 mA) |
