# Development and Application of a New Apparatus for Moisture Measurement in Building Composites
## 3 Methods
### Description of the Measuring Assembly  
A functional control system for measuring water permeability of four samples of building composite was designed. As shown in Figure 2, the new device enables measurement of the actual amount of liquid that the test sample passes over time at a defined hydrostatic pressure. The present apparatus is designed to measure samples with a maximum thickness of 20 cm, and for different sample shapes (square, rectangle, or circle).  
Figure 1: The water barrier consists of three laminate layers, i.e., nonwoven layer (**A**), nanofiber membrane (**B**), and nonwoven layer (**C**).  
As illustrated in Figure 2A, the carrier part is made of light alloy and the horizontal parts are made of plastic boards. The device has nine plastic containers. The highest point of the device is the liquid container (A), which is a common container for four measuring sets (D). Each of the four sets consists of three parts: hydrostatic, testing, and measuring.  
The hydrostatic part, consisting of a top container (A) water reservoir, pipes (B) and two types of valves (C2, C3) is connected by screwing with a rubber gasket. Since the liquid container is located on the sliding profiles, it is possible to adjust the additional pipe (B) and thereby change the height of the water column or the hydrostatic pressure applied to the test samples. Two valves are located above the plate. The plastic board forms the main support of the device, which is also a dividing plane between the hydrostatic and the testing part of the instrument.  
The upper larger valve (C2) is used to close the pipeline, and it is therefore not necessary to drain all of the water when changing the sample, or some of the assembly can be shut off from the measurement process. The smaller lower valve (C3) serves to vent the assembly during water filling. The valve (C1) is a flow meter that records the water absorption of the material.  
The testing part consists of four containers for the test samples (D), which are clamped between two horizontal plates. The plates are controlled by a mechanism by an electric motor. The top horizontal plate has a 3 mm silicone layer in addition to the supporting profiles on the underside. This provides a watertight layer between horizontal plate and the upper edge of the test containers. The silicone layer is fully laid across the underside of the board, allowing variability in the use of different shapes of test containers (circle, square, rectangle).  
The measuring and evaluating part consist of collection of four containers for water and platforms with a weighing sensor (E). The weighing sensor records the mass increments of the liquid Q [g] at time t [s]. The weight gain data is stored in the control unit (F) for further processing. The output is a graph describing the dependence of weight of the flow-through liquid on time, which can be observed on-line on the display.  
The electronics also control the height of the liquid in the upper reservoir. This container is equipped with a float that sends a signal to the control unit, then the change in the level is evaluated, and in the event of its drop, the pump starts, and the water is added from the bottom lower reservoir (G).