TEST CHAMBER ASSEMBLY THEORY OF OPERATION

TM 10-1670-305-23&P 0005 00-1 TEST CHAMBER ASSEMBLY 0005 00 THEORY OF OPERATION THEORY OF OPERATION (MODEL 452) The test chamber components are arranged according to the schematic diagram. The air compressor supplies compressed air at 40 PSI. It is used to cock the AR2 being tested and provides controlled air pressure to the altitude chamber. The rate at which air is introduced into the altitude chamber controls the simulated rate-of-fall of the AR2. When in operation, if the air solenoid valve is opened by positioning the CLIMB/FALL/COCK switch to COCK, compressed air flows into the air cylinder and forces the piston to the right. This will cock the AR2. When the CLIMB/FALL/COCK switch is moved from the COCK position a vent in the solenoid valve allows the compressed air behind the piston to bleed off, thus enabling the AR2 to actuate under the appropriate conditions. Compressed air is also available to the PRESSURE CONTROL regulator, which controls the rate at which air is introduced into the altitude chamber. Outlet pressure from the PRESSURE CONTROL regulator is registered on the pressure (PSI) gauge. Air thus regulated passes through a restrictor and on into the altitude chamber. By controlling the pressure, the simulated rate of fall of the AR2 may be varied. The vacuum pump is connected to the altitude chamber through the ALTITUDE CONTROL regulator, which allows selection of any desired altitude up to 35,000 feet. When the CLIMB/FALL/COCK switch is moved to the CLIMB position, the climb solenoid valve opens. Turning the ALTITUDE CONTROL regulator knob allows selection of the desired altitude. Turning the knob counterclockwise will increase altitude. When the CLIMB/FALL/COCK switch is moved to the FALL position, the climb solenoid valve closes and the restrictor in the line from the PRESSURE CONTROL regulator allows controlled air pressure to enter the altitude chamber, causing the altitude to gradually decrease. The RAPID FALL dump switch (push button) controls the dump solenoid valve. When the RAPID FALL dump switch is pressed the dump solenoid valve opens, and air from the compressor is introduced directly into the altitude chamber for rapid descent. The ON/OFF switch controls power to both the air compressor and vacuum pump. When the air compressor and vacuum pump are running, the indicator light will illuminate. It will extinguish when the ON/OFF switch is positioned to OFF.