Doser 2.1 Calibration issues

reeferfoxx · Feb 23, 2018

Just purchased the 2.1 and before I updated the firmware to 1.28, I was running 1.27. I was playing around with the settings and calibration to get familiar. To say the least I was impressed and found that calibration was easy and accurate.

That said, after updating the firmware to 1.28, I reset the settings and decided to get thing rolling for real. Went to calibrate at the fasted setting, it's starting point was 12 ml/min. I ran the calibration on the fastest setting and the end result was 39 ml/min. I changed the deviation and tested a dose of 20ml. The result was 21ml.

So, I calibrated again. Same thing. 21ml. So I entered 10ml and it dosed 11ml.
Calibrating the 3rd time, I wrote 40ml/min instead of 39ml. Ran a dose of 20ml and again it came out to 21ml.

Am I doing something wrong?

Support@GHLUSA · Feb 23, 2018

If all you’re dosing is 20mL, I would run at a lower speed. Longer runtime will yield a better calibration.
How are you calibrating; what are you using to measure your effluent with?

Generally speaking, unless I do ATO, I almost always run at speed 0.

reeferfoxx · Feb 23, 2018

Marco@GHLUSA said:
If all you’re dosing is 20mL, I would run at a lower speed. Longer runtime will yield a better calibration.
How are you calibrating; what are you using to measure your effluent with?

Generally speaking, unless I do ATO, I almost always run at speed 0.

Thank you so much for the fast response! I'll give it a shot at lower speeds.

I'm using a Labstock 100ml glass graduated cylinder.

Support@GHLUSA · Feb 23, 2018

If you have a scale that can read down to to 0.1g’s then you can try that as well

reeferfoxx · Feb 23, 2018

Marco@GHLUSA said:
If you have a scale that can read down to to 0.1g’s then you can try that as well

I do!!

Got it calibrated perfectly! Thank you! I did 20ml and 20.1ml and the scale didn't lie! Much appreciated thank you!

Support@GHLUSA · Feb 23, 2018

reeferfoxx said:
I do!!

Got it calibrated perfectly! Thank you! I did 20ml and 20.1ml and the scale didn't lie! Much appreciated thank you!

I’ve ordered and received a few graduated measuring beakers/vessels just like yours above. Most of them weren’t accurate! Of course the ones I ordered didn’t come from laboratory supply vendors, rather from the amazing bookstore

reeferfoxx · Feb 23, 2018

Marco@GHLUSA said:
I’ve ordered and received a few graduated measuring beakers/vessels just like yours above. Most of them weren’t accurate! Of course the ones I ordered didn’t come from laboratory supply vendors, rather from the amazing bookstore

I was worrisome about it. I wouldn't have been offended if you told me it wasn't accurate. What is funny is I always use a scale to measure dry goods for dosing. Not sure why that didn't cross my mind to begin with. ;Facepalm;Bucktooth Thanks again!

Brew12 · Mar 1, 2018

reeferfoxx said:
I ran the calibration on the fastest setting and the end result was 39 ml/min.

I'm glad to see this. I ran the calibration on Fast and came up with 37ml. I had no idea if that was in the ballpark or not. I'm just dosing Kalkwasser so I'm not horribly worried about accuracy yet.