Flow Meter to use with Arduino?

Just starting work on a system using Arduino to automate my burners and after some complications this last brew day with the mash recirculation getting stuck, I'm wondering if there would be a way to incorporate a flow meter to know when the flow has stopped and just monitor how fast it's really going. Down the road, I see comparing mash runoff vs sparge water to ensure they're roughly the same.

Can anyone point me in the right direction to some high-temp, food-safe flow meters?

I'd also be interested if anyone has a better solution to help automate/monitor this.

Thanks everyone!!

As far as I know there has not been anyone that has done flow measurement with a Arduino platform, no interface on the Atmel to support the pulse type flow sensors.
Sparge control would take flow metering, level sensing, and some kind of proportional output to control valves that is not possible with the Arduino, so what you want is not currently possible with that platform. If all you need is, timers, on/off, and PWM control then Arduino is the platform for you, more than that and you need to look elsewhere for a more powerful chip than Atmel produces. You need to look at the Cortex M3/M4 series chips and discovery boards from STM, TI, and NXP for 12 bit analog inputs and analog outputs needed to make the sparge control work.

Arduino can do pulse type flow sensors using the analog pins.

kladue may be a bit confused. There's nothing special about using hall effect (pulse) sensors with Arduino, or any microcontroller for that matter. Simply count the pulses as a digital input! Heck, I published my kegerator project here on HBT that uses flow sensors to detect tap flow. Works just fine.

And yes, there are high-temp and food-safe flow sensors as well as proportional valves. Just a matter of $$$.

jkarp said:

kladue may be a bit confused. There's nothing special about using hall effect (pulse) sensors with Arduino, or any microcontroller for that matter. Simply count the pulses as a digital input! Heck, I published my kegerator project here on HBT that uses flow sensors to detect tap flow. Works just fine.

And yes, there are high-temp and food-safe flow sensors as well as proportional valves. Just a matter of $$$.

Click to expand...

That flow meter is perfect! I'm so ordering a few!

mendesm said:

That flow meter is perfect! I'm so ordering a few!

Click to expand...

meh, they arent rated for food, and impeller type flow sensors are impossible to clean, let alone sanitize after use, especially with unfiltered beer with yeast. it has some good qualities (cheap, rated for pressure) but thats about it, i would hardly call it perfect.

just remember that being rated for 80*C only means it is physically capable of withstanding it. if there are any chemicals in the plastic that will leech out, high temperatures increase the rate of leeching exponentially. unless something is certified food grade, you have to assume it isnt. the simple fact that its nylon tells you nothing about its food-grade status.
ive yet to find even a "good" (inexpensive, food grade, better yet- sanitary) flow sensor.


to the original question- the best way to equalize flow rates of sparge water and run off is with a dual head paristaltic pump. one side pumps sparge water from HLT to mash, the other pumps wort from the mash to the boil kettle, automatically at the exact same rate. you can vary the flow almost infinately just by varying the speed of the motor. the only problem is that you cant buy anything like this (for any reasonable price, <$800). i even went so far as to design one in solidworks, i just havnt gotten around to machining it. im hoping that for about $100-200 in materials ill have a dual head pump that uses regular 1/2" ID x 3/4"OD silicone tubing.

audger said:

meh, they arent rated for food, and impeller type flow sensors are impossible to clean, let alone sanitize after use, especially with unfiltered beer with yeast. it has some good qualities (cheap, rated for pressure) but thats about it, i would hardly call it perfect.

just remember that being rated for 80*C only means it is physically capable of withstanding it. if there are any chemicals in the plastic that will leech out, high temperatures increase the rate of leeching exponentially. unless something is certified food grade, you have to assume it isnt. the simple fact that its nylon tells you nothing about its food-grade status.
ive yet to find even a "good" (inexpensive, food grade, better yet- sanitary) flow sensor.

Click to expand...

Those can be used for measuring the water into the HLT pretty easily and since it's cold(er) water it should not be a problem there. At this point, I'm not really looking to use them on the hot side.

It's amazing that some homebrewers can stomach drinking any of their creations at all with the collective irrational fear of every little object in their brewing system.

I'd also hardly say impeller sensors are impossible to clean - most do come apart, but frankly, that's not even worth the bother in a sub $10 flow sensor. Just replace it periodically. Sanitization is only relevant for surfaces that touch cool, unfermented wort. Waste of money sanitizing anything pre-boil, really.

My apologies for the statement that the flow measurement was not possible, I stand corrected for my lack of information on the Arduino platform capabilities.
Be careful with threaded connections and sanitation, I have suffered from lapses in sanitation with threaded and swagelok fittings on the cold side of the CFC and had to disassemble and steam sanitize to kill infection problem.

100% agreed kladue. I've gotten positively paranoid with cold side handling in the past year, and maybe I'm crazy but my beers have tasted better for it. Now, my wort / beer never sees the light of day from boil to when it's pulled from the tap.

Alternately, if you don't need to actually measure flow so much as merely know that it's happening, I've been very happy with a Gems flow switch as a safe-guard on my RIMs recirculation. The body is stainless, though the actual mechanism is a polymer of some sort.

Arduinos, as others have said, can handle this and much, much more. I'll never understand the antipathy towards them.