Barometric sensor enclosure box for FrSky telemetry

This is an enclosure box for a FrSky barometric pressure sensor used in model aircrafts to measure the (pressure) altitude. The purpose of the enlosure with it´s one point vent nipple, is to allow for the builder to decide where the static pressure best is probed in order to measure the true altitude. Just mounting the sensor inside the fuselage can be problematic due to spurious pressure fluctuations induced by propeller wash or ram air pressure from cooling vents. In my case the ducted fan inside an Avanti model caused suction so during motor runup on ground the pressure altitude indicated above 100 meters (300ft)!

The solution was to put the FrSky barometric sensor inside this airtight box and feed it static pressure through its nipple via a hole in the fuselage sidewall.
In many cases it will not be practical to mount the enclosure box direct on the fuselage wall - then instead you may connect a pneumatic tube (or silicon fuel tube will do great) to the nipple and route it to where the pressure probing should be located.
If you have a pitot tube installed then the static pressure works great for this purpose, just use a T-coupling to split between airspeed sensor and baro sensor.

The box needs to be fairly airtight for obvious reasons, meaning i recommend gluing the box halves together and make sure the cable passthrough is sealed against air leakage.

Enjoy