Nu finns de första maskinerna ute hos kunder, följande tips kan vara till hjälp.
Bifogar också två bilder på den helt fabriksnya maskinen, som nu anlänt.
Tack för allt stöd:-)
/Jonas
Användbara tips (ursäkta Engelska, hoppas ok)
Tip 1: tip for those who wants to sharpen the accuracy This is not mandatory, but we have always different demand of perfection.
Tip 2: Very important to remind for all users
Tip 3: A little helpful and very easy tip
See picture
Tip 1:
The measure cylinder you use for calibrate the pumps, are of course not 100% accurate. If you are lucky, the cylinder you got are spoton, but the difference can vary. This is true for all measure units. So if you wants to sharpen the accuracy in calibration, you can "calibrate" your own measure cylinders, with a scale with reasonable precision and a resolution of at least 0.1g.
Method: Be sure the cylinder is absolutely dry. Place it on the scale and press tare. Now pour down RO-water, until you read 10.00 gram. Now you now you have 10.00 ml in the cylinder. Read carefully what cylinder says. If it for instance says 9.5 ml then you have to multiply all your measure cylinder readings with this cylinder, with 10/9.5=1.05.
Same procedure for the bigger cylinder with 50.00 gram etc.
Tip 2: The pipe from pump B, must always be in contact with the bottom glass of the test-vial. This is obvious and we emphasize this in the manual. BUT, as this pipe is not fixed with clips, you can if you are not careful, by mistake, dislocate the pipe from the correct bottom position. Make sure it is really pushed all way down, with close contact with bottom, and make sure that is is not dislocated, for instance when you manipulate with he other pipes and/or closing the door etc.
Tip 3: Every measure cycle takes 50.00 ml water to measure. That is why you calibrate the pump A in this case, to get this 50 ml as accurate as possible. After a while, maybe 2-4 weeks, the hoses changes slowly its properties, and that is the cause that we need to recalibrate the pump from time to time. A very rough but still helpful tip to estimate if the Pump A is doing almost correct (for instance if you have to troubleshoot), you can do this one time for all:
Take the measure cylinder, with no contents, dry. Place it on a high precision scale and pour RO water to 50.00 gram, OR fill it with 50.00 ml RO water with a pipette with god accuracy. Now you know that it contains exact 50.00 ml water. Now, replace the testvial, with these 50.00 ml water still there, and replace all pipes, ph electrode and magnetic rod, in same positions as when running the machine. Now look carefully the water level, and place a mark at that level.
Now, you can when machine taking water to measure look at this mark and see if the machine is very close to this mark exactly before starting to titrate. If it is, you know that you have a quite good accuracy from pump A and maybe do not have to test it with "test pump accuracy". A quick test to exclude that as a cause if you have problem with accuracy.
/Jonas