Gas concentration measurement method - using ultrasonics to determine gas to air ratio in gas filled double glazing esp, for sulphur-hexa:fluoride

摘要

The effectiveness of double-glazing for sound and heat insulation can be greatly enhanced by filling the volume between the sheets of glass with a heavy gas such as sulphur hexafluoride. The problem with producing gas-filled double-glazed elements on a large scale is that the proportion of gas to air must by carefully controlled to achieve optimum insulation. The method of checking the gas/air proportion by placing an ultrasonic transmitter on one side of the frame and a receiver on the other. At frequencies of about 2 MHz, the proportion of gas to air will be inversely proportional to the amplitude of the received signal.