Dual Dosing Pumps - Not Balanced

[hilgert]

I just ran some tests on my new dual dosing pump from TPS. While the online documentation says the pumps will pump 0.75ml/minute, I am getting much more than that. With a 10 minute test I got about 1.00ml/minute. I just completed a 100 minute test to get more precise measurements.

After 100 minutes I had 101ml in one container and 94ml in the other - not good for a "balanced" solution addition system. Certainly I could calculate how much less/more water to add to one part or the other to compensate, but the point is that a 6% difference is adequate for a balanced dosing system.

Both tests were done with RO/DI water.

I'd be interested in any feedback the TPS folks, or others, could provide.

-Hilgert

[Snarkys]

we are going to stop selling these for this reason. our vendor told us that this would not be an issue and in our testing it wasn't but the inside diameter of the tubing seems to be not as consistent as we would like . this has only happened in like 1-20 units but that's way too high : ( This is really to bad because we really wanted to stock an extremely affordable dual head option like this but it just doesn't seem like it is going to work out...

If you would like to send it back for a full refund or credit it towards two single head pumps , please contact us [email protected]

[Snarkys]

BTW we will continue to sell the single head pumps and you can adjust them to your needs by adding or subtracting a minute or two with your digital timer .

[TracyZeuner]

I know you told me you were going to send me new tubing, are you still sending it out or should I send the unit back?

[Snarkys]

i don't think you ever told us your address to send it to : (

my expectation "now" is that it wont be a 100% perfect balance all the time because of the variance of the inside diameter of the hose .

feel free to send it back . let me know if you are interested in two single head pumps.

BTW you will receive much faster service by emailing us at [email protected] or [email protected] . I only check this forum as i have time . emails we check all day long.