Teledyne’s LGA-4000Z series leverages the latest in Tunable Diode Laser Absorption Spectroscopy (TDLAS) to achieve an ultra-fast gas measurement in-line without resorting to extraction and sample conditioning. By tuning the laser to a specific absorption wavelength, based on the gas of interest, the attenuation of the light through a sample cell and the detector can be correlated to the concentration of each gas, per Beer-Lambert Law. The laser provides a narrow absorption band which minimizes the effect of interfering compounds in the process.
The System
The LGA-4000Z consists of a transmitter, receiver and connection box. The transmitter drives the tunable diode to emit a laser of a certain wavelength to pass through the environment being measured until it reaches the receiver. The receiver then performs a photo-electrical conversion, signal processing and spectrum data analysis to obtain the measuring result. The connection box, containing the I/O Interface, makes the connection of the power cable and the signal cable convenient.
Wavelength Modulation Spectroscopy (WMS)
WMS is a method used to significantly increase the sensitivity by reducing the low-frequency noise. The laser light’s intensity is modulated at a high frequency to create a periodic signal to the detector. The signal is then encoded and measured at a high frequency, eliminating the effect of low frequency noise.
Gas Detection Parameters
Gas
| Min Range
| Max Range
| Detection Limit
|
Acetylene (C2H2)
| 0-50 ppm
| 0-100%
| 0.5 ppm
|
Ammonia (NH3)
| 0-10 ppm
| 0-100%
| 0.5 ppm
|
Carbon Dioxide (CO2)
| 0-1000 ppm
| 0-100%
| 40 ppm
|
Carbon Monoxide (CO)
| 0-1000 ppm
| 0-100%
| 40 ppm
|
Ethylene (C2H4)
| 0-100 ppm
| 0-100%
| 1 ppm
|
Hydrochloric Acid (HCl)
| 0-100 ppm
| 0-50%
| 0.1 ppm
|
Hydrofluoric Acid (HF)
| 0-20 ppm
| 0-50%
| 0.05 ppm
|
Hydrogen Sulfide (H2S)
| 0-100 ppm
| 0-100%
| 5 ppm
|
Methane (CH4)
| 0-200 ppm
| 0-100%
| 10 ppm
|
Oxygen (O2)
| 0-1%
| 0-25%
| 0.01%
|
Water/Moisture (H2O)
| 0-100 ppm
| 0-100%
| 0.1 ppm
|
