I started Building the Ventilator described in DRM127. However i can not understand the pressure sensor used in the air chamber. At the benining the air chamber will have the ambient air pressure (~101 kpa) and by adding the air & Oxygen we will get higher pressure however the used pressure sensor can measure until 100 kpa max, moreover in the Code if the pressure exceedes 110 kpa then it is ignored. Is the pressure sensor really correct or am i using it wrongly??