Ghl doser 3 back siphoning

[suikerspin]

Hey r2r,

Ive received a new ghl doser 3 this friday. Ive been spending all weekend now trying to get it not to back siphon.

Its only head 1 & 2 that back siphon. Ive checked the cables theres no holes in it. Only thing i noticed is that the tubes attached to the dosing head on both are longer then the ones on 3 & 4.

Ive adeed some pictures, anyone seeing any issues or can help me before i open a support ticket with ghl.

 

[BeanAnimal]

For it to back siphon the tubing has to be open, which means that it is not being fully occluded by the rollers. I have had a lot of problems with Doser 3 heads stalling and with low speed consistency. I gave up testing due to time and didn’t check for siphoning or full occlusion.

@Lasse thoughts?

 

[suikerspin]

Yeah its doing 0.2ml dosing every time so its running at a low speed is that whats causing it? Would diluting the solution so i can dose more at once help?

 

[BeanAnimal]

Yeah its doing 0.2ml dosing every time so its running at a low speed is that whats causing it? Would diluting the solution so i can dose more at once help?

The issue isn’t the dosing amount. In theory and practice the rollers should pinch the tubing shut and prevent siphoning.

How fast is the siphon?

 

[suikerspin]

The issue isn’t the dosing amount. In theory and practice the rollers should pinch the tubing shut and prevent siphoning.

How fast is the siphon?

it varies sometimes its empty within the hour example: last night i primed it before bed, woke up it was still primed, hour later it completly drained