Simtronics GD1 MK3, Operating Manual

Page: 7 / 76

GD1 Page 7 of 76 850-816926-EN R06
1. INTRODUCTION
1.1. The system
The GD1 is a laser-based open path Gas Detector with a separate transmitter (TX) and
receiver (RX). The TX emits infrared laser light detected by the RX. The detection principle
is based on measuring the absorption of light by the gas molecules along the optical line-
of-sight.
RECEIVER TRANSMITTER
1.2. Definitions
TX Transmitter
RX Receiver
Absolute
transmission Strength of the optical signal
Relative
transmission The relative strength of the optical signal in percentage relative to the
Absolute transmission when finishing alignment.
During commissioning, the GD1 is set up with optimum alignment and
signal strength. The relative transmission is used to keep track on how dirty
or out of alignment the system has become after the GD1 was
commissioned.
Laser light