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GDS HAVCD
 
What is it?
 
The High Accuracy Volume Change Device (HAVCD) provides a simple, high resolution, high accuracy alternative to traditional volume change devices. The device is used to measure volume change along a pressure line. The most common application for the use of the HAVCD is during unsaturated testing where accurate measurement of both small and large pore volume change is critical.
 
High accuracy volume change device (HAVCD)
  Download full specification datasheet as pdf [41kb]
 
 
 
What are its uses
 
The basic principle of the HAVCD is to record the change in the height of the water column inside a vertically orientated tube connected to the drainage line. The pressure head in the
tube is measured using a low range, high-accuracy differential pressure transducer.
The water volume change is equal to the change in the water level multiplied by the cross section of the tube. The accuracy and resolution of the water volume indicator depends on the cross-section area of the tube connecting to the drainage line. Three tubes with inner cross-sectional areas of 28sq mm, 63sq mm and 196sq mm are installed as standard in the apparatus (see Fig. 1). Through a series of valves, the user can choose one or two of the three tubes according to the expected water volume change.
 
 
 
 
 
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