sensor to measure balloon pressure accurately

I'm looking for an air pressure sensor that should only be switched on now and then, or just uses very little energy. Range: no idea what the pressure range is inside very thoughre-usable balloon (any recommendations? maybe a condom :stuck_out_tongue: ? ), but around that range, the sensor should be sensitive.

Any recommendations? Compatible with arduino microcontrollers of course.

Would this pressure sensor be able to tell when the air inside a balloon reaches a certain pressure (no idea what the pressure range is inside balloon , but around that range, the sensor should be sensitive)? There seems to be no real manual provided for pin 1-6... .

Or one of these?

Hello there!

I did some looking and I found this article that has some interesting data, as well as a pinout on the sensor.

While reading the article, I did notice that the output of the sensor only ranges from 0-25mV, so you will have to make use of an amplifier to bring that range to 0-5V (if you are using a 5V board).

The article also lists links to one or more datasheet, so make sure to look at those too.

Give it a read and let me know if it is helpful.

combining that DIP-sensor with HX711 is an inexpensive, simple combo

An alternative would be one of the many automotive MAP (Manifold Absolute Pressure) sensors available on ebay. They already deliver a 1-5v output that can be read directly by an analog pin. Some sensors are available in the $4 range. The automotive MAP sensors usually have a proprietary connector so if you want a sensor with a pigtail included, they are in the $8 range. Slow boat shipped from china of course.

ebay link

There is also something called "Digital Barometric Pressure Sensor Module Liquid Water Level Controller Board" shown on ebay and aliexpress in the $5 range that appears to be that same 40kpa sensor with some kind of amplifier already built in. Unfortunately I don't know how to interface with it.

Wires, probably.

If this graph for a typical party balloon is in the ballpark, you'd only be using about a sixth of the range of a 40kPa sensor (pops at about 50 mm Hg or 1 psi or 6.7 kPa gauge pressure). But maybe that's good enough for you.

Image from this link...from this YouTube video.

Stay away from the millivolt sensors. You can buy sensors with the amplifier and temperature compensation on board.

Honeywell make a number of different ranges which all have similar specifications. Prices go up to about $80 USD before you get to the really advanced stuff. Stay away from the RSC sensors - I've had no luck getting them to sense

Freescale (or whatever they are called now) make a good range with prices around $12 each. I like the MPXV series but they have a couple of options available.

The pressure that the balloon 'feels' is the differential pressure. You need a two-port pressure sensor. The MAP and other barometric sensors will measure absolute pressure, which tells you nothing about how tightly the balloon is stretched.

If the project/experiment duration is short enough, the gauge (differential) pressure inside the balloon can be determined using a sensor that returns absolute pressure by subtracting the atmospheric pressure at the beginning (or end or average of the two) from the measured pressure (same as in the image in reply 6, which shows absolute pressure). If the duration is too long, then variations in atmospheric pressure could confound the results using that approach.