Overview permeable properties of the instrument used to measure various types of geotextiles, its performance in line with GB / T15789-2005 "permeable geotextile performance test method" standard requirements for instruments. Second, the principle under specified conditions, determined by single vertical geotextile water flow. Third, the main technical parameters 1, the maximum head pressure: 250mmH2O (2450Pa) 2, holder inside diameter: ф50 ± 0.5mm 3, maximum sample thickness: 20mm 4, time counter: 0 to 99.99 5, thermometer range: 0 ~ 506, cylinder: 1000mL (10mL) 7, Power: 220v 8, instrument appearance: 400 × 500 × 850mm 9, Weight: 25kg four, instrument by instrument structure frame, container, holder, control line, the control circuit composition and other parts. ? (See Figure - Outline) 1, frame 12 is equipped with front control panel, the panel is equipped with [work] button 8 times counter 9, the power switch 10, a time counter can be time setting. Machine is equipped with four adjustable seat below 13 feet, adjust the feet to maintain the level of the instrument. Base built with solenoid valves, piping and other components. 2, the holder 21 positioned support pins 19 placed inside the container 6 through. Inner and outer containers fused, each outlet in fluid communication with, the holder fused with plexiglass water cylinder 4, the next holder of an open hole plate, pressed by the compression nut 20 under jaws, the sample was clamped in the middle of the holder. Holder placed in the positioning of the support pin 19, the water level has graduated cylinder four side panels toward the direction to facilitate observation. 3, the water inlet 18 external regulator, flow control switch 5 is turned on and the flow control flow size, time counter control solenoid valve action to convert to determine the overflow outlet 17 or 11 out of the water intake. Press the [work] key 8, the time counter 9 start time, when the time counter has not reached the set value, the overflow water from the water discharge port 11, this time with a container of water will flow out to collect all the test port, and then measure the cylinder collecting water; When the time counter reaches the set value, the solenoid action, then discharged from the drain water overflow 17. When the test is complete, hit the open outlet 18 switch, the water drained within the instrument. 4, the control circuit five, working conditions 1, the instrument should be placed on a flat, stable work surface height to facilitate the operation is appropriate. 2, the water pressure is stable, pressure fluctuations should not be too large. 3, ambient temperature: 10 ~ 25 ℃ 4, Power: Ac220 ± 10% 50Hz grounded reliable. Six steps 1, clamping specimen: Remove holder 21, loosen the compression nut 20, the sample is placed on a flat plane of the lower gripper, the pressure on the holder, and then tighten the compression nut 20 the holder mounted on the pin 19 is positioned and supported. 2, turn on the power switch 10 is set in the time counter 9 collection time value (time counter this instrument range from 0 to 9, 99.99 seconds, according to GB / T15789-1995, set the time)> 10 seconds) 3, determined to put Outlet 18 is turned off, the water inlet 16 external regulator, turn the flow control switch 5, the water spout 2 cylinder 4 to align the instrument water until the water level exceeds the height of the contents of the sample plane reaches 6, at this time head pressure is zero. 4, until the water level continues to post stable water, the water began to spill the contents, regulating the flow control switch 5 controls the flow of water has been fixed pressure that the water level 4 cylinder water level stable, then who is discharged through the overflow drain 17. After five, steady pressure until the head 30 seconds, press [work] key eight, nine-time counter starts counting, while the outlet valve conversion, this time by 11 out of the overflow water intakes. A container for collecting water flowing, and then measured cylinder specific value, accurate to 10mL (amount of water collected should be> 1L, such as less than 1L, where appropriate, to increase time setting value); after the set time is reached, the solenoid valve action, When the overflow is discharged from the water drain port 17. 6, during the same time on the steps, read the temperature on the thermometer 3, the water temperature should be at 10 ~ 25 ℃ (accurate to 0.1 ℃). 7 Repeat steps 6.3 to 6.6. Received a total of five sets of readings, flow velocity uniformly distributed between 0mm / s-60mm / s. When the test done from a high flow rate is low. 8 Repeat steps 6.2 to 6.7, at the same pressure the remaining samples tested. 9, turn off the power switch 9, unplug the power cord 14. 10, hit the open water outlet 18 will be left inside the instrument emptying. 11, the test data according to GB / T15789-2005 treatment.