Te​ledyne’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 g​as, 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