The CO sensor we use for air quality measurements is an electrochemical sensor. These kind of sensors require a certain amount of time to detect the gas, from 0.5 seconds up to 3 seconds for small concentrations, and they require a turbulent flow parallel to the membrane . Therefore, it is not possible to just place the sensor with the sensitive surface outside of the aircraft. At the same time, if the sensor is placed inside, an effective way to have air from outside over the membrane must be found.
In order to solve the problem and to guarantee the desired flow over the sensor an air mixing chamber was designed.
The sensor chamber is made of two main parts: the air intake and the air mixing chamber. The air intake is placed outside the fuselage and it collects the air at cruise speed. In the mixing chamber the velocity is decreased and a recirculating vortex is created over the sensor, in this way it has the time to detect the gas before the flow goes away through the exit duct. Changing the mixing chamber volume allow to have a specific recirculation time and thus to measure the concentration with the desired sample rate. The pieces were made using 3D printing.
Avionics Switch - Mobin and Alessandro
The sensor requires certain amount of time to stabilize once it is connected to the circuit. The battery consumption is much faster when the sensor is connected in series with the avionics components. Moreover, connecting the avionics after the sensor is calibrated would take much longer.
This can be avoided by creating a parallel circuitry that splits into two sections:
- One where the battery is connected directly to the sensor
- Other connected to the avionics system
This is done by means of high amp toggle switch. This switch circuitry helps in assembly time as the avionics system is switched off while the sensor stabilizes and can be turned on prior to flight check to reserve the battery power.
Boom Connection - Yusuf Iqbal
The connections between tail boom/fuselage and tail boom/tail of aircraft are the same in principle. This involves the square section boom entering through a square hole and stopping at a circular hole where a screw extrudes outwards of the boom tips on both side and are screwed from the other side of the circular holes with the help of nuts.