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  #26  
Old 01/25/2005, 07:32 AM
Mr James Mr James is offline
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Poor Habib. I'm with Kip!! Instead of trying to fill the little blue spoon half way, Habib ought to make a half spoon and if we want to double it up, we can. I can't wait to hear the fedback on this unit.

Freed: I'd pay $250 for just such a thing, but finding the money in the budget will be interesting. I'll pay $65.00 for a light bulb that only asts one year. People will pay the money if they believe it will make life easier.
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  #27  
Old 01/25/2005, 07:41 AM
grim grim is offline
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Things I'd love to know:

How frequently must it be calibrated
How is it calibrated, is solution provided?
How often must the probe be replaced?
How much is the replacement probe?
What is the accuracy +/-?
What is the precision? 100s 10s 1s .1s?
Can the monitor run submersed 24/7 or is it only for intermittant testing?

Too many questions!
jb
  #28  
Old 01/25/2005, 07:49 AM
Habib Habib is offline
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Poor Habib. I'm with Kip!! Instead of trying to fill the little blue spoon half way, Habib ought to make a half spoon and if we want to double it up, we can.

Don't worry about me.

FWIW for the low res using a half spoon is not critical. It does not change the value. If it is say 25% more or less, it would not matter at all.

If there more questions about the amount of that powder added vs effects then you're welcome to come to the Salifert forum and I'll give more details about it.
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  #29  
Old 01/25/2005, 04:19 PM
Randy Holmes-Farley Randy Holmes-Farley is offline
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FWIW, I'll likely report any testing results in a reefkeeping.com article.
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  #30  
Old 01/25/2005, 05:14 PM
Tagareef Tagareef is offline
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Randy...Hope your talking about the February issue!
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  #31  
Old 01/25/2005, 05:30 PM
ReeferAl ReeferAl is offline
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Quote:
Originally posted by Tagareef
Randy...Hope your talking about the February issue!
You're kidding right? That's a bit much to expect.
  #32  
Old 01/25/2005, 06:02 PM
Tagareef Tagareef is offline
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uh - yeah...I was kidding
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  #33  
Old 01/25/2005, 06:28 PM
Kip Kip is offline
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Quote:
Originally posted by Habib
Poor Habib. I'm with Kip!! Instead of trying to fill the little blue spoon half way, Habib ought to make a half spoon and if we want to double it up, we can.

Don't worry about me.

FWIW for the low res using a half spoon is not critical. It does not change the value. If it is say 25% more or less, it would not matter at all.

If there more questions about the amount of that powder added vs effects then you're welcome to come to the Salifert forum and I'll give more details about it.
man... i was counting grains in a spoonfull and dividing in half

... i tried using a Ca selective eletrode a couple of years ago... that thing drove me crazy.. i got a feeling i will be measuring out those blue spoons for years to come

what some needs to invent is the robot to use the sali-kits for ya... now theres an invention... but then again.. that just takes all the fun outta being a hobbyist

thanks for the info about the 1/2 spoon-thing
  #34  
Old 01/25/2005, 06:52 PM
bachtor bachtor is offline
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Some of your answers:

How frequently must it be calibrated

Frequent calibration is recommended. Fresh calibration fluids should be used when old fluid becomes contaminated.

How is it calibrated, is solution provided?

Looks like a 100 and 1000 ppm solution is provided.

How often must the probe be replaced?

Per instructions, every 18-24 mnths.

What is the accuracy +/-?
What is the precision? 100s 10s 1s .1s?

Resolution: 000.2 ppm
Accuracy: +/- 2% of the reading after calibration

Can the monitor run submersed 24/7 or is it only for intermittant testing?

Looks similar to the pH montior--both, but must be capped if stored.


Here's the link:

User guide
  #35  
Old 01/25/2005, 07:11 PM
Boomer Boomer is offline
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Ok. my turn There are Alk monitors @ $ 8,000 by HACH, APA 6000. There is also a Ca monitor, another 8 grand . Both monitor a sample stream and perform titrations of that stream. They run for 1 month then you have to refill the reagent bottles.

New tech in seawater for ISE

http://www.wpiinc.com/WPI_Web/Biosensing/ION.html

Grim

Can the monitor run submersed 24/7 or is it only for intermittant testing

This bothers me also. I wound wonder about abiotic precip on the probe.
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  #36  
Old 01/25/2005, 07:53 PM
mattseattle mattseattle is offline
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I think it's meant more for casual testing and not constant monitoring.
  #37  
Old 01/26/2005, 09:39 AM
pomme pomme is offline
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Just interested to hear why it said earlier in the thread that iks/neptune are unlikely to come out with a probe+adaptor so you can monitor the ca?

Andrew
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  #38  
Old 01/26/2005, 10:38 PM
Mr_Quality Mr_Quality is offline
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Randy,

Let me know if I can help with Minitab analysis or anything (pretty please). Are you planning any kind of regression tests against Salifert or ICP? How about a nice gage R&R study. I know your wife can do it too, but I'd have more fun!

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  #39  
Old 01/26/2005, 10:48 PM
mhurley mhurley is offline
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Quote:
Originally posted by pomme
Just interested to hear why it said earlier in the thread that iks/neptune are unlikely to come out with a probe+adaptor so you can monitor the ca?

Andrew
Andrew,

Strictly my opinion here....Many reefers have been asking Neptune for a few years to put out an upgraded controller with a second pH probe (to control a calcium reactor). After 2+ years of waiting for the AC3 which was just released...no second probe. I'm not expecting them to jump off the dime to integrate a brand new probe.

Now this new Aquatronics controller from Italy seems to have some promise...very expandable, unlimited number of probes..etc. But we don't know much about it yet and not sure if it could handle a Ca probe.

Quite honestly, if this probe turns out to be worth it, every Neptune owner (including myself) will be sending emails to them requesting integration...But I have no expectations of that happening quickly. So if his probe is worth anything, I'll be buying a stand alone unit to sit next to my Aquacontroller.
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  #40  
Old 01/27/2005, 08:34 AM
MickyB MickyB is offline
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Mike,

If you want 2 probes on the aquacontroller all you have to do is buy 2 aquacontrollers..Ha..

Mike
  #41  
Old 01/27/2005, 12:00 PM
Randy Holmes-Farley Randy Holmes-Farley is offline
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What I'm thinking to do with the probe is something like this:

Take some clear, settled IO salt water at normal salinity. Determine the calcium by ICP/AA using standard additions of calcium ions (acidified and filtered and also not acidified and filtered, to show that it is all in solution).

Then determine the calcium in that non acidified IO with the probe.

Determine the calcium in IO that has standard additions of calcium.

Same for standard additions of magnesium.

Determine the calcium concentration as the IO is diluted slightly with DI water.

These tests should show whether the probe is basically accurate, and how it is impacted by magnesisum and salinity.

If anyone has other suggestions, I'm happy to consider them.
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  #42  
Old 01/27/2005, 03:48 PM
Freed Freed is offline
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Whatever you come up with, Randy. You're the chemist and I will take your word for it.
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  #43  
Old 01/27/2005, 04:15 PM
kbd kbd is offline
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Randy,

Would it also be possible to repeat the basic tests, say, one week and two weeks following calibration ? Eg full strength and half strength IO ?

Hopefully you wouldn't need to redo the ICP/AA (whatever that is....sounds very posh though).

Might frustrate some of your eager readers, whose US dollars are burning holes in their pockets (not surprised, they'll be worth nothing soon.... ). But I think some stability is key for the casual user, especially those looking to spend US$250 to save time and trouble.

Just a thought....

kim
  #44  
Old 01/27/2005, 05:34 PM
Scuba Dog Scuba Dog is offline
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I would be interested to see if it maintains its accuracy at various concentration levels...
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  #45  
Old 01/27/2005, 05:58 PM
Randy Holmes-Farley Randy Holmes-Farley is offline
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I would be interested to see if it maintains its accuracy at various concentration levels...

Yes, that is what the plan is: "Determine the calcium in IO that has standard additions of calcium."
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  #46  
Old 01/27/2005, 07:16 PM
Mr_Quality Mr_Quality is offline
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Escuse me if I'm getting carried away, but how's this:

Gage Reproducibility & Repeatability Study
To determine the sources of variability (based on ANOVA)
To be performed at a single level of interest, say 400 ppm

Factors:

Replicate (take 3 measurements per time point per operator)

Day (perform measurements over different days, you can decide if you want to space the days apart over say weeks and you can decide if you want to recalibrate each time)

Operator (have 2 or 3 different people take the measurements to see if there is a technique component)

This could be done for the probe and again for a reagent based kit for comparison.



Regression Study:
To test for linearity, proportional and constant bias relative to another method.
To be performed with several samples (I’d recommend at least 10) that span the entire linear range of the device or reagent test.

Assay the samples by the probe and assay the same samples using either a reagent based test or a reference method like ICP/AA.
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  #47  
Old 01/28/2005, 05:59 AM
dgasmd dgasmd is offline
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Quote:
Originally posted by mhurley
Now this new Aquatronics controller from Italy seems to have some promise...very expandable, unlimited number of probes..etc. But we don't know much about it yet and not sure if it could handle a Ca probe.
Mike:

Can you comment more abou thisAquatronics controller? PM me if you prefer to keep the thread on track.

Alberto
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  #48  
Old 01/28/2005, 01:20 PM
Bojan Bojan is offline
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Randy , do you have any results about this Pinpoint Ca Monitor until now. I am planning to order one next week.
  #49  
Old 01/28/2005, 01:23 PM
Randy Holmes-Farley Randy Holmes-Farley is offline
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No, I haven't taken it out of the box yet, and may not be able to do these experiments for a while.
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  #50  
Old 01/28/2005, 10:41 PM
chask chask is offline
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Just saw this thread referenced from another about the Ca ion meter. Does anyone know if this works as advertised? I have seen others that I think do a few other ones that are also of interest.

http://www.qasupplies.com/cardyionmeters.html - NaCl, Nitrate, Na, and K.
I think they are made by Horiba - http://global.horiba.com/products_e/.

WTW also makes some http://www.wtw.de/us/index.html.

I have never purchased one but I like the idea. Anyone out there have any idea how well they work? It would be nice to know about repeatability, stability of calibration, accuracy, etc. Seems like they would be much easier than test kits, and possibly far more accurate (not so prone to operator error).
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