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Precision Sensor Board

I recently designed a board that incorporates digital pressure, temperature, and dewpoint sensors I’ve called the PTU board. I deal with weather balloon tracking systems and the information sent back from the radiosondes is usually called PTU data (Pressure, Temperature, and Humidity).

I’ve written 2 new Arduino libraries for the pressure and temp and reused an existing library for the humidity sensor. You’ll notice in the readings that all 3 have temperature sensors embedded in them. One is a little higher than the temperature sensor itself and one is a little lower. Guess if the temp sensor failed you could average the other two for a good reading :). Current output using Arduino based boards is as follows:

Absolute Pressure : 987.42 mBar
Relative Pressure : 1021.95 mBar
Pressure: 30.18 inHg
P_Sensor Temp: 21.69°C
P_Sensor Temp: 71.04°F
T_Sensor Temp: 21.45°C
T_Sensor Temp: 70.62°F
Humidity: 38.07%
U_Sensor Temp: 21.20°C
U_Sensor Temp: 70.16°F
Dew Point: 6.58°C
Dew Point: 43.84°F
Heat Index: 69.17°F
*****2-Minute Averages*****
Avg_P: 30.18 inHg
Avg_T: 70.60°F
Avg_U: 37.84%
Avg_DewPt: 43.67°F
My only issue now is to figure out how to properly house one of these to make it a viable sensor to place outdoors. You can find electronics enclosures all over the place, but finding “probe” enclosures that you could place a breathable filter on the end seems to be very difficult. 
Any feedback or questions is welcome!
Sensor Info:
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Heather Brooks
8 years ago

Great post! Thanks for sharing it and for featuring it in the Gadget Showcase.

8 years ago

Hi Rick
Great to see, and I like the specs on the devices you’ve chosen.
Have you a reference or a plan on where you might release the libraries – software and hardware design.
Mechanical enclosures are a challange, and unfortunately, if you are doing a real-world design for a specific environment (weather balloon?) its one of the starting points. The other starting point is power budget. One way of talking about this is how the device is used – the lifecycle of data collection.

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