User manual VAISALA LT31 BROCHURE

[. . . ] Vaisala Transmissometer LT31 Measures Visibility with Maximum Reliability and Minimum Maintenance. P. O. Box 26, FIN-00421 Helsinki, FINLAND Tel: +358 9 894 91 Fax: +358 9 8949 2485 Email: metinstruments@vaisala. com www. vaisala. com Vaisala Transmissometer LT31 RVR with New Eyes Features/Benefits Featur es/Benefits · Single baseline for the measurement range 10. . . 10 000 m MOR · State-of-the-art white light source · Automatic alignment with quality control as a standard feature · Automatic calibration as a standard · Window contamination compensation · Sophisticated self-diagnostics · Internal back-up battery · Meets the ICAO and WMO requirements for RVR and visibility · Based on decades of field experience · Compatible with Vaisala Transmissometer MITRAS and SKOPOGRAPH II Flamingo The Vaisala Transmissometer LT31 enables the accurate and reliable single baseline measurement for CATIIIb category airports. Accurate and reliable determination of the Runway Visual Range (RVR) reduces airport downtime and improves safety of operations. The Vaisala Transmissometer LT31 is the qualified observer of RVR providing correct visibility data without interruptions and with minimal maintenance. which makes measuring easier and more economical. provides White LED provides wide spectrum source spectr um light sour ce The LT31 incorporates a white LED as a light source. [. . . ] The alignment quality is also continuously evaluated without any human intervention. The automatic fine Automatic calibration with forwar ward integrated for war d scatter sensor Calibration of a transmissometer is traditionally based on human observations. A reliable and accurate calibration has required very high visibility, stable conditions, and skilled and well trained personnel. The integrated forward scatter sensor. True window contamination compensation based on V-shaped windows. alignment also provides easy handling of the LT31 during installation. The alignment quality during harsh weather conditions is ensured by a double mast construction. The outer tube behaves as wind and solar radiation shield. The inner support structure is separated from thermal and mechanical stress caused by solar radiation and wind load. Automatic window contamination compensation Window contamination is a significant source of error in transmissometers. Maintaining high accuracy has required frequent cleaning. However, the effects of contamination can be automatically compensated if the window transmittance can be measured accurately. In the LT31, the contamination is compensated by the most accurate method: by measuring the transmittance of the window directly through the window glass. Present repor eporting Pr esent weather r epor ting The optional present weather reporting from RVR sites gives a full picture of the prevailing weather conditions within the whole airport area. The arrival of weather fronts and the presence of local showers can easily be monitored due to the multiple present weather observation points. The integrated present weather sensor provides the type and intensity of precipitation for METAR and local weather reporting purposes. reduction Contamination r eduction In general, precipitation leads to an increased amount of window contamination. The LT31 has long and narrow weather protection hoods that reduce the amount of window contamination caused by precipitation. For wind driven precipitation or dust the instrument is equipped with a powerful blower. The blower creates an air curtain in front of the instrument window. The air curtain is specially designed not to disturb the measurement path and cause the measurement errors that have been a problem with traditional blower designs. Extensive self-diagnostics The LT31 incorporates a sophisticated self-diagnostics that leads to detailed status information for all functional units. In addition, the self-diagnostics feature helps to locate possible technical failures. [. . . ] The LT31 assists the installation personnel via the service terminal and offers acoustical support during set-up of the instrument heads. The final alignment is carried out automatically. Ref. Box 26, FIN-00421 Helsinki, FINLAND Tel: +358 9 894 91, Fax: +358 9 8949 2485 Email: metinstruments@vaisala. com [. . . ]