An often overlooked, but extremely useful feature.
Why would you need this feature?
This article considers that you are already familiar with the Emec VCO Pump but if not, you may want to visit the product information page first.
Human beings have a natural tendency to oversize things. Mentally we somehow 'feel' that bigger is always better. In many cases that may be true but not when it comes to dosing pumps. In our experience we see many customers who perceive that a 6 L/Hr dosing pump must be better than a 2 L/Hr model because of its larger capacity. If the application only requires 2L/hr or less, then there is no advantage in choosing the 'bigger' pump.
This is one reason why we encourage people to seek advice from our sales team, since they know what to ask in order to select the right product for the best outcome and with your best interest at heart.
The Emec VCO is a delightfully simple pump. Just an on/off button and a single dial graduated from 0% to 100% comprise its controls. A fixed stroke length pump, the dial simply adjusts the frequency at which the solenoid works. The VCO has two modes of operation: a Normal dosing mode, and a 1:10 Divider mode, which allows greater control and tune-ability when working at low dosing rates.
How does the 1/10 divider work?
You can see in the picture below there is a dial with a range of Zero to 100% which is set as required to achieve your desired dosing rate. When the required dosing rate is 10% or less, the 1:10 divider should be engaged.
Even when a pump has been correctly sized & selected sometimes it is necessary to operate at low %pump speed and this is when the 1:10 Divider mode shines.
Trying to adjust the pump to a dose rate of say 6% will be a fiddly exercise and you may find yourself chasing your tail if in Normal mode. Tiny turns of the dial may have a larger than wanted effect on the pump's output. (It is actually mentioned in the instruction manual that linearity problems are likely to occur if running in Normal mode below 10%)
So...what to do?
To engage the divider first switch the VCO off. Now, push and hold the "on" button for about 4-5 seconds until the LED blinks and note that the LED has changed colour, it was yellow / green before but now it's orange.
At this point, the 1 in 10 divider is engaged. What that means is, the entire scale of zero to 100% on the dial only covers zero to 10% of the pump's duty. Your 2L/hr VCO pump is now a 200mL/hr VCO pump.
So if we turn the dial right up to 100%. We've actually just set it to 10%. Turn it down to 80%, It's now on 8% . Set 25% on the dial? that's 2.5% duty. In 1:10 Divider mode you have superior fine tune-ability for lower dosing rates. Much better than trying to tweak it a tiny bit up and down, each day to find the sweet spot (if at all).
I've used this feature frequently and it's good one to know about.. It's also worth remembering that someone may accidentally engage the Divider mode and not understand why the pump wont run as fast as it usually does. Easily fixed. You disengage the divider mode the same way you engage it. Switch the VCO off, then press & hold the on button until the LED blinks back to green.
If you'd like more information or a demonstration or brain-storm about your particular dosing needs, please contact us using the form below and ask for me...