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I expect my first laser (40w china) to arrive Tues. or Wed. and one of the first things I would like to do is to add a flow sensor to it. I have a flow sensor from tankless hot water heater and have written code for a PIC that senses the flow. The PIC can set the flow rate sense point via a pot and lights a green LED when flow is good. If flow falls below the set rate, a relay will shut off the tube PS and flash a red LED.

The flow sensor from the water heater would work but it is kinda large and will require odd mods to get fittings on it, it's designed to slip on with O rings and special clips. So I was looking at the Koolance and Futrelec ones, my question is, what size should I order ? 1/4" or larger ?

Thanks for your advice on this,

Steve

Wow, almost 120 views over 9 days on this and not one word of advice ??? I don't quite understand that !

Anyway, I went ahead and ordered the one from Futurlec as seen below, I see no reason why this one won't work well with the system. It's not important to me for it to be clear and actually view it working as it will be mounted out of sight and will be monitored with the PIC. Maybe this will help someone else at some point with the same question.

Many views might come from google hits on "flow sensor". Others might just be lurking and not want to weigh in. That sensor looks fine. I saw them at Alibaba.com for about $4 each if someone is willing to import them in quantities of 50 or more. (Looks like a good LightObjects product!)

The smallest restrictions in the system are located at the tube ends where it drops to an oriface of less than 1/4". There is no need to size your tubing any larger than 1/4" id anywhere in such a small water loop.

Thanks for your reply, I didn't know googleBot registered as a hit but I can see why it probably does. After getting my KIII up and running and looking at the tubing size and flow rate I felt pretty good about ordering that sensor.

Appreciate the help

I saw this post but had no input so said nothing. I suspect many of your hits were as simple as that. Got a link for where you snagged that sensor? Thanks!

-Mike

mikegrundvig wrote:I saw this post but had no input so said nothing. I suspect many of your hits were as simple as that. Got a link for where you snagged that sensor? Thanks!

-Mike

Sure Mike, here it is: http://www.futurlec.com/Flow_Sensor.shtml

That is a most excellent price. I also like the one a little lower on the page that includes temperature and flow readback. I've got one in the shopping cart now. Merry Christmas to me!

lasersafe1 wrote:That is a most excellent price. I also like the one a little lower on the page that includes temperature and flow readback. I've got one in the shopping cart now. Merry Christmas to me!

Where are you seeing the temperature?

From their description : "This unit displays the current Flow Rate as well as the total amount of Water that has passed. "

Oops my mistake. It said Temp 0 to 60 degrees C in the "features", but this doesn't mean it displays the temperature, only that it handles the temperature. I bet the flow gets pretty slow at 0C unless you have anti-freeze in your system.

I thought that's what it meant the first time I read it too. Yeah, I think I'd be pretty slow at 0c also

I do want to have temp display though, so similar to what Bart was doing, I'll be mounting the LCD in the panel with flow rate and temp info. It's just something else to make it nicer for me, not really necessary I guess. Still have to make the PCB for it. But that's last priority right now, first is to switch to DSP

Picture didn't turn out too good...