0871LH1 Freezing-Rain Sensor

The 0871LH1 uses resonant frequencies to determine the presence of icing conditions. Its main component is a nickel alloy rod that has a natural resonant frequency of 40 kHz. As ice collects on the rod, the added mass causes the resonant frequency to decrease. When the frequency decreases to 130 Hz (or 0.02-in. layer of ice), an internal heater automatically defrosts the sensor. 

Wind Energy Applications 

The 0871LH1 can detect ice on a wind turbine’s blade, which is undesirable because: 

• • Blade can throw large chunks of ice a considerable distance—an extremely dangerous, potentially lethal situation. 
  • Formation of ice can cause unbalanced loading on the turbine’s blades, bearings, and gear box. 
  • Ice reduces the turbine’s power output. 
  • The 0871LH1 can be used for wind prospecting applications by helping predict the amount of time a potential wind power site may be out of commission due to icing conditions. Additionally, the sensor lets users know when ice is preventing their wind sensors from providing data. 

Benefits and Features 

Can be used to help prevent damage to power lines, and to warn of icy road hazards, ice on planes’ wings, and ice on wind turbine blades 

Automatically defrosts itself when ice accumulation reaches 0.5 m