Transmissometer LT31 The world’s best, most accurate, and most frequently used visibility measurement instrument for runway visual range. Cutting-Edge Visibility Technology Cutting-Edge Visibility Technology Image Transmissometer technology provides today’s best visibility measurement accuracy for Runway Visual Range (RVR), and Vaisala’s LT31 is the most trusted and frequently used transmissometer the world over.By measuring light attenuation (reduction in light) between the transmitter and receiver, the LT31 is thus independent of the type of visibility reducing particles present — ensuring the best accuracy in the most crucial low-visibility situations, and in all conditions.It automates many critical functions to provide unmatched accuracy, outstanding uptime, and minimal maintenance needs — ensuring the safety and efficiency of your airport operations Download brochure Compliant & Cost-Effective Compliant & Cost-Effective Image With LT31, airports have the necessary information to ensure safety of runway operations while maximizing capacity during all types of weather. Other benefits include:Simplified compliance — Meet ICAO requirements and national and local certifications for CAT I to CAT III airports.Fail-safe operation: Transmissometers report lower-than-actual visibility if there is a disturbance to the measurement.Low maintenance costs: Extensive self-diagnostics, ruggedness, and automation mean maximum uptime and minimized maintenance. Download brochure Features At A Glance Features At A Glance Image The features that make the LT31 transmissometer the gold standard:Vaisala-patented automatic calibrationAutomatic alignmentIntelligent contamination avoidance and compensationMeteorological Optical Range (MOR) of 10kmFull compliance with ICAO and WMO requirementsWhite LED light sourceStraightforward maintenanceOptional present weather reporting Download brochure When Only the Best Visibility Measurement Accuracy Will Do Don’t wait. See why the LT31 from Vaisala is the most trusted and frequently used transmissometer for RVR in the world. Contact us Resources Brochure A Clearer Approach to RVR Learn about principles and solutions for accuracy and reliability. Download PDF Product Spotlight Transmissometer LT31 Discover how to access the industry's most accurate runway visibility data. Download PDF Datasheet Transmissometer LT31 Learn about accurate and reliable single baseline measurement for CATIIIb category airports. Download PDF Success Stories Dirección General de Aeronáutica Civil de Chile Case Study: Monitoring Aviation Safety in Diverse Climates SUCCESS STORY: Vaisala helped ensure flight frequency and safety in vastly different climates and locales. Read more