Teledyne LGA-3500 - Laser Gas Analysis system - Manual (Page 44)

Operation Model 3500
Teledyne Analytical Instruments 30
Figure 4.7 Numerical Value Mode of the MainMenu
The meaning of each item on the menu is listed below:
• Current concentration: the gas concentration value just measured
• Average concentration: gas concentration value after digital
filtering. It can alleviate the influence caused by the uncertainty
of gas flow.
• Standard dev: standard deviation of the measured gas
concentration.
• Gas temperature: the temperature of the gas under test.
• Gas pressure: the pressure of the gas under test.
• Ave. times: Number of times used in digital filtering.
• Trans: Transmittance of laser beam in the environment under
test. If the optical windows in the transmitter and the receiver are
contaminated by dust in the environment under test, or if the
optical path between the transmitter and the receiver deviates
from the optimal position, the transmittance decreases.
• Con. output--4mA: gas concentration value corresponding to
4mA of the 4-20mA gas concentration output.