Back to product search

Vaisala CL31 Ceilometer

Vaisala Ceilometer CL31 measures cloud base height and vertical visibility in all weather – good or bad. Backscatter profiling performance and reliability in all weather conditions up to 25,000 feet (7.6 km). It is a compact and lightweight instrument for cloud base height and vertical visibility measurements. It detects three cloud layers simultaneously. The CL31 employs a pulsed diode laser LIDAR (light detection and ranging) technology. The CL31 is ideal for aviation and meteorological applications.

The enhanced single-lens technology applied in the CL31 ensures excellent performance starting at a height of virtually zero. This is due to the strong and stable signal over the whole measurement range. The single-lens technology provides unsurpassed reliability during precipitation, low clouds and ground based obscurations, which are the most critical phenomena in aviation safety.

Fast measurement helps to detect thin cloud patches below a solid cloud base. The CL31 provides a full backscatter profile for data visualization and research purpose. The CL31 beam can be directed either vertically or tilted. The tilting option together with the novel optics design provides enhanced performance during precipitation by improving the protection given by the shield. In the measurement unit, a tilt angle sensor automatically corrects the measured cloud distance reading to vertical cloud base height.

Vaisala CL31 Ceilometer Features
  • Fast measurement enables detection of thin cloud layers below a solid cloud base
  • Extensive self-diagnostics with fault analysis
  • Approved and deployed by the US-FAA
  • Selected by the National Weather Service of USA
  • Measurement range from 0 to 7.6 km (from 0 to 25,000 feet).
  • Second-generation, advanced single-lens optics provides excellent performance also at low altitudes
  • Reliable operation in all weather; unsurpassed performance in vertical visibility and cloud detection during precipitation
  • Modular design for easy installation and maintenance
  • Fast measurement enables detection of thin cloud layers below a solid cloud base
  • Latest technology from the world-leading manufacturer – based on the experience from more than 5000 installed Vaisala ceilometers worldwide

Fluidic are a recognised distributor of Vaisala MetOcean instrumentation for Scotland and the North of England.  Our instrumentation engineers are product trained and able to help with instrument selection within the full range of Vaisala instrumentation.  Please call either office for more information (Glasgow 0141 641 5920,  Warrington 01925 572401).


  • Download Vaisala CL31 Datasheet
  • Download Vaisala CL31 User Guide
  • Download Sky Condition Algorithm for Vaisala Ceilometers
  • Download Vaisala MetOcean Brochure
  • Download Vaisala News Article on the CL31 (2005)
Enquire about this product
Your Name *
Please call either office for more information: