Pressure transmitter analog input board of adjustment A / D acquisition card is to convert analog to digital interface card, the application uses the ACL a 8316 board, its resolution is 16bit, the output range ± 5V, ± 10V, accuracy of 0.1, the acquisition rate 100KHz. D / A card is to digital converter for analog output interface card, the application uses the PCL-727, the card is a 12bit analog output, the output voltage range of 0 ~ 10V, ± 5V, etc., output accuracy ± 1SB, 16-channel output, the card as well as 16 of the I / O inputs and outputs for control applications. Electrically controlled pressure transmitter electrically controlled proportional valve drive proportional valve control signal based on the outlet to adjust the size, which is the method can be electrically controlled servo-controlled proportional valve control to adjust the valve selection of US production BB2MFIF125 pressure type valves, pressure transmitter adjustment range 0 ~ 60Psi, the control signal 0 ~ 10V. In the control is impossible to D / A analog output direct access to the control end of the valve, thus increasing the servo drives and prevention valve hysteresis exciting unit. Using OPA544 replaced the previous more complex hardware power-driven push-pull circuit. Not only easy to use, and easy to adjust, check. Pressure console when it includes two pressurized electro-pneumatic proportional valve, vacuum when two electro-pneumatic proportional valve, two exhaust pneumatic control switch valve, within the population, exports, as well as the pilot pressure becomes specimen a pressure gauge transmitter monitoring. Pressure console is divided into manual / automatic modes, manual / automatic switch set to automatic position with GCS a digital pressure control system online. Hardware protection hardware protection into contact pressure transmitter protection, emergency protection and power protection are three buttons to quickly open the exhaust valve protection exhaust, suspension test. Protection contact pressure transmitter: the method used in the past to protect the gas tank filling pressure test, because this test can not use gas tank containing negative protection methods, the use of a protective contact pressure transmitter. When positive pressure or negative pressure to exceed the given range after turning the exhaust vent; panic button protection: On the console and handheld pneumatic protection kits are provided with an emergency button (red), press the emergency button to open the exhaust valve exhaust, suspension test; power protection: hardware protection using a solenoid valve is a normally open valve, when no test or a sudden power failure to ensure that no air pressure inside the test piece. Shielding gas tank gas tank protection is the use of poor atmospheric physics, the water level in the ground plane is increased by one meter will have a differential pressure 0.01MPa. In our experiments the maximum pressure of the test piece does not exceed the general 0.1MPa; test charge pressure test pieces are connected by a tube with gas tanks, gas tanks filled with water, the definition of the protective tube (depending on the test pressure is determined the height of the tube), and the test pieces in the water level of the water level is equal to the pipe, with the increase in pressure within the test piece protective tube water rises during the test when the pressure exceeds the pressure value of the test charge, the protective tube The water will overflow protection. When inflating the test, the lower half of the gas tank for water, the upper half of the gas, when the water overflows over-pressure protection, the top of the gas tank has a pressure transmitter can be directly read out the pressure test. The test verifies that the method is simple and practical.

keywords: Transmitter, pressure transmitter,