Monitoring of Tanks Containing De-icing Agents for Aircraft

The process of de-icing removes ice and snow from aeroplanes. De-icing is crucial for safety reasons since ice and snow increase the weight of an aeroplane thus adversely affecting aerodynamics. Aircraft  need to be de-iced immediately prior to take-off so that the protective effect lasts for a sufficient period of time. According to ISO/SAE, there are liquids categorised as types I, II, III and IV which are diluted with water (100, 75 or 50 %) or remain undiluted, depending on the required protection level required. Whether or not an aieroplane is de-iced and what the mixture should be is the decision of the pilot or somebody authorised by the pilot.    

Due to the viscous nature of the de-icing agent, the measuring system in 3 cylindrical tanks with a height of 3 metres at a German airport kept failing or delivering incorrect measurement results. The measuring system was replaced with AFRISO‘s SonarFox UST 10 ultrasonic transmitter,  which solved the problem. The UST 10 is suitable for the continuous non-contact measurement of liquids and bulk solids of a wide variety of consistencies; type, density and temperature.  In addition, the UST 10 can operate in tanks with  installations or stirrers below a suitable level surface of the medium  without affecting the accuracy of the measurement. The ultrasonic transmitter was fitted with a local display for visualisation and programming (programming display PD10 UST). The airport‘s operator also wanted to be able to read the level in the tanks with the de-icing agent from inside the control room so the transmitter was also connected to the AFRISO VarioFox digital display and control unit. The VarioFox is a universal measurement and control unit that comes ready to be connected and includes freely configurable units and scalable start and end values; this allows operators to choose a  wide variety of configurations. Automatic calculation formulas for horizontal, cylindrical and spherical tanks are stored in the device so that a signal that is proportional to the volume can be transmitted and directly displayed. The airport now has a reliable solution and inadequate levels of de-icing agent will no longer cause interruptions to air traffic.