The bell-type device for determining gas permeability 04315 is designed to determine the gas permeability of wet sands and wet, dry or cured samples of molding and rod mixtures according to GOST 23409.6-78.
The device is used for use in shop and factory laboratories of molding materials and mixtures, in laboratories of research organizations. The device for resistance to climatic influences corresponds to the UHL design, product placement category 4.2 according to GOST 15150-69.
The principle of operation and composition of the device.
The principle of operation of the device is based on passing air through the test sample and fixing the pressure drop under it.
A tank is fixed on the frame of the device, inside which a tube is installed, which is an air duct and at the same time a guide when lowering the bell. The bell is toriated by weight and creates a constant pressure of 980.7 Pa (100 mm of water).
Distilled water poured into the tank serves as a water gate.
The air passing through the nipple enters under the test sample and passes through it. The resulting pressure drop under the sample is transferred to a tank with a tinted liquid, which enters a pressure gauge graded in units of gas permeability.
2 nipples are supplied with the device: DN 0.5 mm and DN 1.5 mm. The nipples are calibrated so that the passage time of 2000 cm3 of air under a pressure of 980.7 Pa through a 1.5 mm nipple is 30s, and after 0.5 mm-270s.
The pressure gauge scale is graded for each nipple separately.
If the gas permeability is less than 50 units, a nipple with a DN of 0.5 mm is used.