Set up the deadspace measurement apparatus (A.2.6; see Figure A.3). Close the tap to the oxygen analyzer (A.2.8). Open the ball valve. Connect the resuscitator and ventilale until the balloon fills the container completely and is pressed against the inner walls. Close the ball valve. Open the oxygen analyzer tap. Open the flowmeter and fill the container with 100 % (V/V) oxygen. Close the oxygen flowmeter when the pressure gauge reads approximately 1 kPa (10 cmH20)and close the oxygen analyzer tap.