Alk/Ca Testing

[emissary]

For those of you using the Salifert test kits for Ca and Alk -- when you test, where is your meniscus when your black rubber stopper is lined up to the 1.0ml mark? The "air gap" that is said to not influence the results is all well and good, but I noticed that in one case my meniscus was at 7.5, in another 7.6, and in another 7.2. This meniscus variation will lead to different test results of course and I'm curious where it should be.

[YBeNormal]

I don't remember for sure where it ends up on mine--about .76 I think--but tested it many times a few months ago and it has been very consistent. If yours is varying that much, something isn't right. Make sure the plastic tip is firmly attached and not allowing air to be drawn in.

[dhoch]

I'm confused because I don't see it making sense to me.

 

As long as the air gap is towards teh top of the syringe you are only measuring the distance the plunger moves = only liquid coming out = air bubble doesn't make a difference (you are not measuring how far the liquid move, but how far the plunger moves.

 

Dave

 

PS my newest Alk testkit from Salifert has a different plunger that is much easier to read.

[YBeNormal]

Doh! Good point! I can't believe I didn't think about that as many times as I have explained it to others.

[emissary]

As long as the air gap is towards teh top of the syringe you are only measuring the distance the plunger moves = only liquid coming out = air bubble doesn't make a difference (you are not measuring how far the liquid move, but how far the plunger moves.

 

Duh!#@$! Took me 3 readings of that to understand but ... wow, okay... I gotta lay off the crack.