Chapter 2 __________________________________________________________ Product Overview 
VAISALA _______________________________________________________________________ 25 
Compatibility 
LT31 is compatible to the mounting hole pattern of Vaisala MITRAS and 
Impulsphysik SKOPOGRAPH. The emulation of related serial data 
messages is also a standard feature. 
Introduction to LT31 
The Transmissometer LT31 measurement system consists of one LT31 
transmitter unit (which includes the transmissometer light transmitter) 
and one LT31 receiver unit (which incorporates the transmissometer light 
receiver). Figure 1 on page 26 shows the main parts of the Vaisala 
Transmissometer LT31.