Salifert test DKH air bubble ?

[lanshark]

As I don't see a Salifert home office phone to call in States, could someone please confirm the following;

Using the KH/ALK Profi Test kit that when the instructions say there will be some air below the black tip of the syringe plunger.

Some Air equals air from the 1.0 ml mark all the way to .78 mark?

Do fellow Salifert testers agree ? If so, my dkh tested at 9.6 this morning.

I'm trying to get my ALK and CALC inline before bringing my Calc reactor back online.... Thanks!

[vegaskid11]

I have seen from .76-.79 air line depending on how even I pull the plunger back.

[chuckreef]

Although it won't hinder the measurement result, you should expel that syringe full back into the reagent botttle with the tip of the syringe submerged, and re-draw the 1.0ml. If you do this witht the tip submerged, you should get a much smaller bubble.

[jtma508]

But it should be pointed out that it doesn't make a bit of difference how big the bubble is as long as you don't empty the syringe (which shouldn't ever happen anyway). You are measuring the displacement of the plunger. NOT the volume.

[lanshark]

Thanks everybody. I struggled with JTMA508's answer for awhile, then realized how it is true, coz the bubble is used for displacement at the top while testing drop per drop.

One more question;

Do we agree that the plastic tip MUST be applied to the syringe as part of the test and not done without or it will effect the reading of results?

[dbdisok]

You need the tip in place to draw the reagent and to allow you to add a drop at a time. If you draw the reagent without the tip in place then add it you with throw off your result because the initial forward movement of the plunger will be pushing air not reagent.

[bertoni]

The tip allows a much more precise reading of the alkalinity level. Otherwise, it's unimportant. I don't know what the precision would be without the tip, so I can't say how big the error would be.

[clittrell]

I use the same kit and also get about the same size bubble. I have test against sachem and get similar results with both.

[Randy Holmes-Farley]

As Jonathan mentions, the tip allows smaller drop sizes to get better precision, but does not otherwise impact the results. The air bubbles and volume measurements marked on the syringe are exactly the way syringes are supposed to work, and Salifert fully recognizes this. They have said to ignore the air in the syringe many times in this forum.

[lanshark]

Appreciate knowledge transfer. Let's see? I have 72 posts, and Mr. Farley here has 72....000 posts! Egads! I need to peddle faster .....

Thanks again!