Sprayed bar sprayers for large area spraying of pesticides use a piston diaphragm pump, which is a reciprocating positive displacement pump with pulsating pressure. Diaphragm pump power generally come from the tractor, driven diaphragm pump speed is generally 500 ~ 600r / min to two-cylinder pump, for example, the water pulsation is 1000 ~ 1200 times / min. Outlet pulsation on the spray machine and spray quality are harmful, in order to eliminate pulsation, in such pumps with an important component; gas chamber. The function of the air chamber is to utilize the compressibility (or elasticity) of the air to absorb the pulsation of the diaphragm pump and stabilize it. The structure of the air chamber is generally separated by a rubber diaphragm that separates the water chamber from the air chamber. After filling the air cavity with compressed air, the water in the water chamber is absorbed by the compressed air in the air chamber through the rubber diaphragm, and the flow into the system is basically steady. But to achieve the basic requirements of steady flow, there is a premise that the gas pressure in the gas chamber should be compatible with the water pressure. Thus, before the sprayer should be properly inflated diaphragm pump chamber. How to inflate properly? Method 1 , before the operation of the diaphragm pump, first inflated to the gas chamber, the pressure is greater than the working pressure of the pump. Driven diaphragm pumps, transferred to the working pressure, this time you can see the pump water drastic jitter. Take a needle, the top of the gas nozzle at the deflation, with the deflation, the water hose jitter will gradually disappear. After the water hose steady, stop deflating. Method 2, drive the diaphragm pump, transferred to the working pressure. At this point because there is no pressure in the gas chamber, the pump water hose fierce jitter. Inflation immediately to the gas chamber, with the inflatable, water hose jitter disappear. Stop the inflation after the water hose is steady. The above two methods are operating under the operation, the operation must pay attention to safety.