Vaisala GMT220 - Manual (Page 11)

Chapter 2 __________________________________________________________ Product Overview
VAISALA _______________________________________________________________________ 11
LED Indicators and Optional Display
The GMT220 series transmitter has, as a standard, three LED light
indicators on the cover plate: OPERATION, LEVEL 1 and LEVEL 2 (see
Figure 3).
- The green OPERATION LED is lit when the power is connected.
- The red LEVEL LED S are lit if the relay setting is reached, for example
when CO
2
concentration is over the predefined limit. If the relays are
not in use, the LEVEL LEDs indicating CO
2
concentration are dark.
The transmitter is also available with an optional back lit LCD display,
which outputs the CO
2
volume concentration in unit of percentage or
ppm depending on the measurement range of the probe.
Blinking led lights and Er-codes in the display indicate operation errors,
see Error Messages on page 25.
0807-034
Figure 3 LED Indicators and Optional Display
For GMP221 probe, the display shows percentage values with two
decimal accuracy, for example 0.31 %. For GMP222 probe, the display
shows ppm values rounded up to the nearest 10 ppm.