Vaisala INDIGO520 Industrial Transmitter INDIGO520 A1N2B8AAAN Vaisala INDIGO520 Industrial Transmitter. Model: INDIGO520. Part Number: A1N2B8AAAN. • Vaisala INDIGO520 Transmitter. • Industrial humidity monitoring. • Max Current: 2A. ⚠Important. • No probes or sensors included. byJuly 3, 2026