LTEH211-230 and LTEH211-115 - LT31

LTEH211-230 and LTEH211-115 Installation Guide

Document code
Document type
Spare part manual
User guide

LT31 enhanced weather protection hood provides a high degree of protection against strong wind-driven precipitation. The enhanced weather protection hoods are installed to the support units of the transmitter and the receiver instead of the standard weather protection hoods delivered with LT31. Vaisala recommends installing the optional enhanced weather protection hood especially in locations where high winds in combination with precipitation occur.

The enhanced weather protection hood is equipped with 2 controlled 100 W heating mats to avoid snow accumulation. One of the heating mats is attached to the protection hood and the other to the horizontal plate inside the hood. Both heating mats are equipped with temperature switches to keep the surface temperature below +50 °C (+122 °F). An additional temperature switch in the connection cable of the heater system powers the heaters exclusively when the ambient temperature falls below +5 … 10 °C (+41 … 50 °F).

The following versions are available:

  • 230 V version LTEH211-230
  • 115 V version LTEH211-115

The enhanced weather protection hood consists of the following parts:

  • Assembly with heating system that is mounted on the support unit instead of the standard weather protection hood (including mounting screws)
  • Removable protection hood with heating system that is attached to the assembly
  • Removable bottom plate to close the support unit from below the measurement unit
  • New measurement unit enclosure cover plate with air duct
Figure 1. Parts of enhanced protection hood
Air duct extended hood
Protection hood
Bottom plate
Thumb screws (2 pcs)
Screw, hex socket head, M4x10 DIN7991 A4 (4 pcs)

The enhanced weather protection hood has no impact on the effective baseline length of LT31. Configure the baseline length identically to the physical baseline length. See the section on initial settings in LT31 User Guide (M210667EN).