Vaisala Hydromet Data Collection Platform - Manual (Page 29)

Chapter 2 __________________________________________________________ Product Overview
VAISALA_______________________________________________________________________ 27
Transient Protection Devices
Each sensor input in the logger has a varistor (VDR) protection against
induced transients. The maintenance terminal I/O ports have transzorb
diodes in their inputs.
In case of long signal cables, additional transient protectors can be
installed on the DIN rail. These surge protectors consist of a
combination of VDR, transzorb diodes, and coils, thus providing
excellent protection. These are easy to change in the field without tools.
0802-050 Figure 7 Surge Protector for Serial Lines
Optional coaxial surge protectors can be used for UHF and VHF
antennas as well as for the RF signal input when radio or satellite
equipment is used.