Help making a flow bench manometer processor

You will need a differential pressure sensor. A module like this costs about $40.

The sensor chip without the PCB costs about $10.

This sensor outputs a voltage so you will also need to connect it to a 16 bit A/D converter module that in turn connects to your RPi or arduino. The A/D module will only cost a few $.

The parts are not too expensive, but you will then need to put them in a box and write some software.

The other option is to request a sample from now NXP directly, its one way to keep hobby costs low...

Kas

Hi Anthony,

How's your math skills?

I assume you're using a shop vac or similar as your vacuum (flow) source?

I would recommend two barometer sensors and two temperature sensors.

One set inside your test tube, one to reference ambient air pressure and temp.

It is also recommended to have the inlet pipe about 10 diameters long or better with no bends, kinks or restrictions as a flow straightener, but it depends on the level of accuracy you need.

Doing relative measurements wouldn't require huge accuracy.

After that it's a simple process of sample measurement and calculations, as illustrated here http://hyperphysics.phy-astr.gsu.edu/hbase/ppois.html#poi

A good fluid mechanics textbook will walk you through the equations.

I assume you can handle the programing?

I was looking at a similar setup for checking mass air flow sensors two years ago but owners sold company instead.(bet new owners had a lot of fun with it)

Why stop there, you could put similar sensors on your race car and measure the flow in each cylinder runner under real-world  / real-time conditions.

Bosh sensor in standard mode takes 7.5ms per sample, you could watch the intake port open at up to 16K RPM. (if I did the number right)

(bet the signal will be noisy as ....)

e-bay has these cheap about $3.50US with shipping.

Al