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Introducing our technical Web Helpers!

By Hank Levi on Mon, Nov 23, 2020 @ 01:58 PM

Hello!  Please meet our new Web Helpers!  Moisture Elle, Karl Fischer, Shaker Sam, Terri Tenso, and Vivian Visco!  Each of our helpers will provide technical information ranging from general topics to more in-depth discussion pertaining to; Moisture testing, Karl Fischer Titration, Particle Size Analysis, Surface Tension, and Viscosity.

 

 

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How an oil evaporator works with a Karl Fischer Titrator

By Hank Levi on Mon, Aug 26, 2019 @ 11:13 AM

Evaporators configured for use with Karl Fischer moisture testers can provide added benefit when testing for moisture in samples that are not easily solubilized in the titration cell.  In some cases even if it's possible to solubilize the sample in the titration cell you may find that it is better to use an evaporator to improve repeat testing by keeping the cell clean.  While traditonal Karl Fischer moistutre testing is performed using a direct injection method where a syringe and needle is used to introduce the liquid sample into the titration cell, the use of evaporators follow a different approach. 

Within the evaporator family there are SOLIDS EVAPORATORS that can range from 0 to 300 degree C as well as high heat solids evaporators that can range from 0 to 1,000 degree C. 

A typical OIL EVAPORATOR will have a range from 0 to 300 degree C. 

Solids evaporators will typically be used to measure moisture in these types of samples:

  • plastic pellets (pte, etc)
  • plastic parts (you can cut into smaller pieces with a pair of scissors)
  • paper material (transformers)
  • thick grease samples
  • thick petroleum based samples like heavy paints, etc
  • and the list goes on

Oil evaporators will generally be used when working with heavy crude oil samples with high turnover testing (keeping the cell clean).

In this video we will discuss and show how the oil evaporator works with a Karl Fischer Titrator.

 

Talking points include:

  • Karl Fischer Titrator
  • Oil Evaporator
  • Base Oil
  • Bubbler Tube
  • Nitrogen Gas Source
  • Regulator
  • Thermocouple
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What happened to Hydranal Karl Fischer Reagents?

By Hank Levi on Sun, Nov 05, 2017 @ 08:12 PM

There has been some confusion in the market place when it comes to purchasing Karl Fischer reagents and water standards.  Some of you who have traditionally ordered the Hydranal brand from Sigma Aldrich (and it's channel partners and dealers) are discovering now that the Karl Fischer reagents and waters standards are slightly different - If you order them from Sigma Aldrich.  The names on the bottles are kind of the same, but not exactly.

milliporesigmalogo.png

Some background - what happened to Sigma Aldrich

As many people know Sigma Aldrich for many years handled the Hydranal line of Karl Fischer Reagents and water standards.  Recently (within the past year and a half or so), a company called EMD who controls the other Karl Fisher reagent line called Aquastar purchased Sigma Aldrich.  As a result of this transaction Sigma Aldrich is now part of another company and is referred to as MilliporeSigma.The Sigma Alrdrich you used to know no longer provides the Hydranal brand but intstead now offers the Aquastar line of Karl Fischer Reagents and water standards.

What happened to the Hydranal brand of Karl Fischer reagents?

honeywelllogo.jpgA well-known company called Honeywell purchased and now controls the Hydranal line of Karl Fischer Reagents.  You can still order Hydranal brand coulometric Karl Fischer reagents and volumetric Karl Fischer reagents via Honeywell and it's channel partners and distributors.

What does this mean to you and how might this effect you?

As you can imagine this has triggered a lot of phone calls with questions from end-users to purchasing agents with questions like:

  • Are these reagents the same?
  • Can I use these reagents interchangeably?
  • What are the differences?
  • Hydranal vs. Aquastar?

Here's what we know

As a manufacturer and distributor of coulometric Karl Fischer titrators and volumetric Karl Fischer titrators for many years, we have worked with both the Aquastar and Hydranal brands extensively.  We are not here to tell you one is better than the other.  We can tell you that different model Karl Fischer titrators seem to work differently depending on the brand of Karl Fischer reagent used.  It might simply be an operators familiarity with working with one brand vs. the other or it might be because a specific application just works better with a certain Karl Fischer reagent.  

-While the design is that either of these brands should work we find subtle differences in chemistry-  

Are there any real key chemical differences between Hydranal and Aquastar?

To be fair we have not reached out to Aquastar for their perspective yet (we will - and update this post).  From the Hydranal technical center we have obtained some information about what they see as strengths in the Hydranal brand and some differences with the Aquastar brand.  Here are a few notable points:

1. Different performance.  Yes they do perform differently.

2. Different solvents are used.  Example:  Aquastar Combititrant is a copy of the old version of Hydranal Composite 5 where there was no 2-Methylimidazole.  Without 2-Methylimidazole, you can have reagent crystalization and stability issues.

3. Co-solvents are optimized in Hydranal.  Too much Chloroform can mess up the stoichiometry

4. Hydranal coulometric reagents are more unique

  • Hydranal has more buffering capacity
  • Larger volume of samples than Aquastar

5. Hydranal is very precise, convenient and consistent

As mentioned above we hope to get some additional information on the Aquastar line so we can share with you their strengths and differences.  In the meantime we hope this information has been helpful.

If you have any questions or would like to compare the reagents you currently use with the "other" brand just let us know.  We can provide a cross reference for all of the Karl Fischer reagents by brand and product.

Learn More

As always, we hope this information is helpful.

 


 



 

 

 

 

 

 

 

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Review of KEM's new titration line

By Hank Levi on Tue, Jun 09, 2015 @ 04:11 PM


Review of KEM's new titration line 

AT-710S_M Automatic Titrator

I don't know about you but I have to admit that I enjoy learning about new technology.  Whether it's smart phones, cars, or kitchen appliances I think it's fun to find out about how a product has changed (hopefully for the better). For the most part a lot of consumer products see a change or upgrade about once every year. This is not really the case for titrators where maybe it's only every 6 to 8 years before we see a new generation unveiled.  I guess that's why I thought maybe it would be a good idea to take a look at this new 710 series that came out in February 2015.  I haven't actually ever written a "review" before so I decided to start by comparing what I know about some of the current titrator models and identify the things that pop out with the new titration line.   Here are my observations and comments.


  

1. There are now three model levels; entry, mid-level, and flagship within each category (volumetric Karl Fischer, coulometric Karl Fischer, and automatic potentiometric titrator) 

Find more Coulometric Karl Fischer Titrator information

My comment: I like the scale of the models as it can be helpful for those with varied budgets and needs.  I like the concept that you can start with getting only the basic model at first and then later bring in the flagship model and tie them all together into one system.  It will be interesting to see how people approach these options and whether the ability to expand a system is desirable or not.
710_series_titrator_with_2_burettes

2. All of the automatic titrators now can accommodate two burette drives

 AT-710 AutomaticTitrator information

My comment: The automatic titrators come with one burette drive but being able to add a second burette drive allows an operator to run two separate titrations (titrants) without having to use an automatic piston burette.  Historically most titrator manufacturers offered only a single burette drive but it seems like this is changing.  It's kind of a big deal for those who run two different titrations and don't want to purchase an automatic piston burette.  I like this new capability.

3.  A new burette design for the automatic titrators and volumetric Karl Fischer titrators.

SmartBuretteUnit

My comment: The burettes appear they will be easier to store and swap as the titrant bottle, burette and nozzles all go together as one smaller unit.   The burettes are now "smart" burettes and can store all of the reagent information within the head of the burette.  I like this.

Learn more about Volumetric Karl Fischer Titration

4.  More Input/Output options for operators to move  and store data.  I/O options include LAN connectivity/URL, USB hubs, USB thumb drive ports, .CSV file format, .PDF file format, barcode readers, foot switches, and keyboards.710seriesUSB

My comment:  More technology is built into these units. I think it was overdue so I am glad to see it finally arrive.

AT710_w_propeller_or_magnetic_stirrer

5.  Automatic Titrators now come with a propeller stirrer by default but can swap for a magnetic stirrer instead.

My comment: I like the option to do both but I think maybe the magnetic stirrer should have been the default and the propeller as the option.

 

6.  A new Wireless/ Wired 8.4 inch color touch panel controller (MCU).

MCU_screen_view_with_multiple_units

My comment: This only comes with the mid-range and the flagship models.  The controller can sit next to the titrator or be carried around like a clipboard.  Operators can control the titrator through protective glass if necessary.  I'm not sure how many people will elect to use the wireless vs. the wired connection but it's nice to have the added capability.  Nice.

7.  Multi-titrator integration.  The wireless/wired MCU can control up to 4 different titrators simultaneously (any combination of Karl Fischer or automatic titrator) 

MCU_controller for 710 series titrators

My comment: This feature is reserved for the flagship model.  I can see this being useful for those needing to run both moisture and acid for example.  Unfortunately the mid-level model MCU cannot be upgraded to the MCU flagship model so if you think you might expand later don't go with the S model.  Your better off getting the basic "B" model and then later tying them all together from the flagship model.

 710seriesmulticontrol

8.  Free method making software.

My comment:  All of the titrators now come with a CD that allows you to create methods on your PC and then transfer methods to the titrator.  You can also pull methods off of the titrator and edit it in the PC.  The software also comes with various popular methods pre-loaded to help get methods setup quicker.  I'm not so sure how robust this software is but free is nice.

CDstoredmethods
 
 
 
 




CONCLUSION:

Well I hope this was helpful in finding out quickly what the updates are for the new 710 series.  At this point since it's so new we will have to wait to evaluate how customers feel about their user experience and get their feedback on what they liked most and what they liked least.  If you have any questions or comments you can email me at info@scientificgear.com



 

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How to use Karl Fischer Grease

By Hank Levi on Sun, Jan 19, 2014 @ 01:57 PM

Karl Fischer GreaseCertain types of Karl Fischer vessels require the use of Karl Fischer grease. Vessels with smooth port openings need a thin layer of the grease applied to plugs, electrodes, dessicant tubes, bubbler tubes and injection port plugs to help form a snug fit.  Decreasing or limiting "ambient moisture" from getting into the vessel - otherwise known as "drift" - is the key benefit of using Karl Fischer grease.  Another benefit of Karl Fischer grease is that it also helps prevent chipping of glass on glass fittings.  Watch this short video to see how Karl Fischer Grease should be applied.

Learn more about Karl Fischer Titration
If you find this information helpful please consider subscribing to our blog.  Once you subscribe you will get notified when we post a new article.

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How do Ketones & Aldehydes affect Karl Fischer moisture testing?

By Hank Levi on Mon, Sep 23, 2013 @ 04:32 PM

Measuring moisture using a karl Fischer Titrator is a common and popular choice among operators.  Karl Fischer titration provides excellent accuracy at the part-per-million (PPM) level and is widely accepted and trusted as a reliable method for measuring moisture.  Ketones and Aldehydes however are two organic compounds that can cause problems and lead to errors with measured results if they are present in a sample during testing.  The presence of these organic compounds can create an unwanted side-effect inside the titration vessel.

 ketoneWhat are the side-effects?   aldehyde

The effects are side-reactions that can either falsley increase your moisture results or falsley reduce your moisture results.  Depending on whether your dealing with ketones or aldehydes or both you will want to know how to deal with them.  

How do you solve the problem?

Once you have identified the problem you need to take stock in your equipment and the chemical reagents you are using.  The equipment setup and reagent choices you make can help you to suppress these side reactions and obtain accurate results.

Watch this short 3 minute video to learn about the preferred equipment setup and your chemical reagent choices.

 

 On a sidenote who knew that Ketones have an impact on the human body? Check out this cool review

Just thought it was interesting and wanted to share.

                           Still need help? Click here.

 

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Karl Fischer Over Titration and 7 things you should know about it

By Hank Levi on Wed, May 02, 2012 @ 06:30 PM

We have all seen it.  We’re running a test to see how much moisture is in our sample when inexplicably the liquid inside the Karl Fischer vessel starts to turn from a normal light-yellow color to a dark burnt-red looking color.  Sometimes the titrator screen will inform us of the problem with a digital readout stating the dreaded

OVER-TITRATION!” 

kfbeforestart resized 600describe the imagedescribe the imagedescribe the image

 

Sometimes the digital readout says nothing at all.  In either case the operator knows something has gone wrong because the Karl Fischer Titrator is no longer giving moisture results.  A panic to figure out the problem and get testing underway again becomes the immediate priority. 

But where do you start?  

As it turns out “over-titration” is probably one of the top 2 or 3 complaints or issues we hear about from operators.    So what is causing this problem to occur?  How can we determine the source of this problem, fix it, and more importantly how can we avoid it?

 
This is a critical question for operators and managers working in a production or QC environment who are concerned with keeping their Karl Fischer Titrator 100% “in-service”, day-in and day-out.   Having the ability to identify the problem correctly so appropriate measures can be taken quickly is very important.

 
So how do we approach the problem of “over-titration”?   By knowing the facts.  Having a clear understanding of the process can help operators correct the problem faster when time is of the essence.  

Important facts you should know about over-titration:  
  1. Over-titration is a state where there is more iodine present in the vessel than water (general definition).
  2. When over-titration occurs the vessel will become very dark as a result of the abundance of iodine present inside the vessel.
  3. The reagent inside the vessel should normally have a light-yellow color absent a very dark sample such as oil.
  4. The Karl Fischer Titrator always attempts to maintain an equilibrium where only enough iodine is introduced to counter and neutralize the water present inside the vessel.
  5. During a single titration test there should only be enough iodine introduced to counter and neutralize the amount of water present inside the titration vessel during that test – no more, no less.
  6. Any incident that interferes with the final amount of iodine introduced during the titration test can lead to dis-equilibrium and result in more iodine being introduced than necessary.
    Important facts you should know about Karl Fischer Titrator Glassware:  
  1. The Karl Fischer Vessel and Glassware is composed of the following
    1. Vessel (coulometric and volumetric)
    2. Generator Electrode (coulometric only) - The Generator Electrode is a precision electrode designed to deliver an electrical current inside the vessel to the reagent – causing the reagent to produce iodine
    3. Titration nozzle (volumetric only) - The titration nozzle delivers precise amounts of iodine (composite or titrant) via a burette driven mechanism using a piston
    4. Detector Electrode (coulometric and volumetric) - The detector electrode has a sole purpose and probably the most important role in continuously monitoring and determining the conductivity levels within the titration vessel.
  So what are the causes that can lead to over-titration? 

✓ A damaged Detector Electrode

✓ A "Tricked" or "Fooled" Detector Electrode (no joke)

Since coulometric and volumetric Karl Fischer Titrators handle the delivery of iodine differently it’s worth describing the two methods separately.  

A Word About Coulometric Karl Fischer Titration:

In a coulometric system the reagent is a complete system where it is designed to release iodine when the generator electrode delivers an electrical current to it.  So what causes the generator electrode to deliver too much current causing the over production of iodine?  Another way to say it is, “who or what” is telling the generator electrode to continue to generate a current when it’s not needed?  

   
The detector electrode!  So why would the detector electrode do this?   describe the image
Without getting into too much of the electronics the detector electrode is designed to “detect” conductivity in the vessel.  Depending on the amount of conductivity detected the detector electrode will send a message to the titrator telling it to continue producing a current - enough to release the appropriate amount of iodine to counter and neutralize the water present in the vessel.  As long as this process is working during a titration an eventual endpoint will be found and a result will be produced.  


So it’s really a problem of misinformation. If the Karl Fischer Titrator is not getting the right information from the detector electrode then over-titration is possible. 

The problems we see that can effect the proper functioning of the detector electrode include:  
  1. The electrode cable.  If the cable becomes cracked or breaks it can cause a situation where the message to the titrator is to continue producing a current – continually.  In this case the vessel will become very dark and in most cases the titrator will not even know it is in an over-titration state.  The generator electrode will simply continue to produce a current, turning the vessel very dark.  There will be no other warning or notice from the titrator for the operator to see.
  2. Cracked electrode.  Sometimes mishandling or even a stirrer bar bouncing around inside the vessel can cause a tiny crack near the bottom of the detector electrode that cannot be seen with the naked eye.  These cracks can allow small amounts of reagent inside the electrode enough where errors in detection will begin to occur.  What ensues is an unstable drift that jumps around giving the titrator a misreading. The jumping around and unstable drift may be picked up by the titrator and an error stating “OVER TITRATION” may be seen on the screen of the titrator.
  3. Cable connectors.  Sometimes the connectors on the titrator itself can become dirty, wet and corroded.  Also, some electrodes use multi-plug designs that can also become dirty, wet and corroded.   These connectors if not clean and dry can lead to a similar misreading similar to a cracked electrode where the drift begins to jump around and become unstable.  The titrator may also state that there is “OVER TITRATION” when this occurs.

Find more Coulometric Karl Fischer Titrator information 

A "Tricked" or "Fooled" Detector Electrode you say?describe the image

If it’s determined that the problem is not the detector electrode then we need to look at the stirring action inside the vessel.  If the iodine being released is not mixing well because the stirrer is off or set too low, then the detector electrode will not realize there is iodine already released inside the vessel.  This will cause the detector electrode to continue telling the titrator to produce more current via the generator electrode up to the point where the detector electrode senses a reduction in the conductivity level inside the vessel.  Conductivity only reduces as the iodine interacts with the water.  So it is important for the detector electrode to sense the true and most accurate “mix or state” of iodine and water during the titration process.  If it does not know the true state of the mix it will be fooled into telling the titrator to keep going – causing OVER TITRATION.        

A Word About Volumetric Karl Fischer Titration:

   
describe the imageIn a volumetric system the reagent setup is different where a composite or titrant is introduced via a burette piston through a titration nozzle.  The amount of composite or titrant delivered is based upon the commands of the titrator.  The command from the titrator to the burette and piston that push out the “iodine” through the titration nozzle is, yes, given by the detector electrode.  For the purposes of this discussion the difference between the coulometric and volumetric setup is that the delivery of iodine is different.   But the same problem can occur where the iodine does not mix well and therefore trick the detector electrode in to thinking there is not enough iodine present inside the vessel to counter and neutralize the water.  Since both coulometric and volumetric Karl Fischer Titrators use detector electrodes the problems mentioned earlier about the detector electrode will hold true with volumetric titrators also.  

Learn more about Volumetric Karl Fischer Titration 

 

 7 Thoughts (DOs and DON'Ts) on Problem Solving and Prevention:  

1.  Don’t abuse the detector electrode!  Be very careful with the detector electrode and do not handle it unnecessarily.  Small bumps (clanks) here and there can lead to a crack.   Do you really need to remove the detector thinking dragonelectrode from the vessel all the time?
2.  Don’t turn up the titrator’s stirrer speed to high.  This will only cause the stirrer bar to bounce around uncontrollably and possibly hit and damage the detector electrode (crack).
3.  Do inspect all connections and connectors on the detector electrode cable and Karl Fischer Titrator to ensure they are dry and clean.
4.  Do be careful with the detector electrode cable.  Try not to bend it unnecessarily.
5.  Do make sure there is enough stirring action inside the vessel to mix the iodine around effectively.  A small vortex should be visible.  But not too fast to cause the stir bar to bounce around.
6.  Do introduce some moisture - Sometimes when you are in an over-titration situation and the vessel is already very dark you can introduce a little moisture to bring the vessel back to equilibrium.  This sometimes works and immediately the vessel turns from a dark burnt-red color to a light-yellow.
7.  Do have a spare detector electrode on hand.  This little electrode seems to get over looked but plays a huge role inside the Karl Fischer Titrator vessel.

Created on 05/02/12 at 18:10:44

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What are Karl Fischer Water Standards and what do the numbers mean?

By Hank Levi on Thu, Feb 09, 2012 @ 01:44 PM

Most everyone working with Karl Fischer Titration at some point ends up wanting to check their instrument for accuracy and overall operational readiness.  Karl Fischer Water Standards were made to assist operators with making these operational checks.  Sometimes however we find there is some confusion about the choice of water standards available and what the numbers mean.

Learn more about Karl Fischer Titration

Karl Fischer Titration Water Standard Video from Scientificgear on Vimeo.

Hydranal water standards provide a few popular choices for both coulometric and volumetric Karl Fischer Titrators:

  • Hydranal 0.1 (100PPM ±10% error acceptance)
  • Hydranal 1.0 (1,000PPM ±3% error acceptance)
  • Hydranal 10.0 (10,000PPM)

So what do the numbers mean?  0.1, 1.0, 10.0?

Simply put, these numbers tell us the amount of moisture (H2O) that is present in 1 gram of the water standard.  The amount of moisture (H2O) is expressed as milligrams on the packaging.  Using the Hydranal 1.0 for example we say there is 1.0 milligram of moisture (H2O) in 1 gram of the water standard.  Did you know there are 1,000 micrograms per 1.0 milligram?  Yes there is.  So instead of thinking in terms of 1 milligram per 1 gram of water standard, think in terms of 1,000 micrograms per 1 gram of water standard.  Why?

Karl Fischer Titrators count moisture in micrograms!

Since Karl Fischer Titrators count moisture in micrograms it's easier to think about the water standards in terms of micrograms.  Why?

Find more Coulometric Karl Fischer Titrator information

We evaluate our water standard test in PPM

For the Hydyanal 1.0 we are looking for results within ±3% of 1,000PPM (970PPM to 1030PPM).  For the Hydranal 0.1 we are looking for results within ±10% of 100PPM (90PPM to 110PPM).

 Learn more about Volumetric Karl Fischer Titration

Don't forget this formula!:

PPM = WATER DETECTED IN MICROGRAMS/SAMPLE SIZE IN GRAMS

(For those who don't know PPM stands for Parts Per Million)

We hope this information has been helpful.

 Created on 02/09/12 at 13:36:32 

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Can a Karl Fischer Titrator measure moisture in a solid sample?

By Hank Levi on Thu, Sep 15, 2011 @ 10:33 AM

YES IT CAN!Karl Fischer Titrator

You can measure moisture in solid samples including plastics, powders, ores, gooey substances that are thick and viscous, greases, and many more.  The key is sample preparation to ensure that a uniform material will be tested.  Once those details are worked out the pattern for testing is the same every time. 

You hear a lot about people running traditional Karl Fischer titration using direct injection with a syringe and needle. That’s pretty easy. 

  Learn more about the Karl Fischer 710 Series

So how do you test for moisture in solids?

For more awkward samples like a solid or solid-like substance we can evaluate the moisture using a Karl Fischer Titrator with an Evaporator Oven.ADP611 Solids Evaporator for Karl Fischer Titration

Believe it or not that’s pretty easy too. I guess that’s why we wrote this post. We wanted to let readers know that the process for running a Karl Fischer moisture test using an evaporator oven is not that difficult.  As mentioned already the most difficult part is probably working with your sample. To help show how the process works we created this short 7 minute video detailing the steps along the way. Please make note that the instruments used for this demonstration are the Karl Fischer Titrator (MKC-610DT) and the Evaporator Oven (ADP-611).

Hope you enjoy.

In the video below we show the 600 series Karl Fischer Titrator.  Today we have additional models like the MKC-710 series that work with the ADP-611 solids evaporator.

Find more Coulometric Karl Fischer Titrator information

 

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I'm Having Problems with my Volumetric Karl Fischer Titrator

By Hank Levi on Fri, Jul 29, 2011 @ 11:55 AM

Most operators who measure moisture Volumetric Karl Fischer Titratorusing a Volumetric Karl Fischer Titrator tend to have difficulty in 3 areas.   Unlike Coulometric Karl Fischer Titrators where the equipment setup and reagents are fairly straight forward, Volumetric Karl Fischer Titrators differ greatly.  Understanding how a Volumetric Karl Fischer Titrator differs and how the equipment functions is not only paramount in terms of knowing how to operate the instrument it is critical if you want to obtain accurate and repeatable results.

8 out of 10 questions we receive usually fall into one of these 3 problem areas:

 

  1. What REAGENTS should I use for testing my samples?  Titrants, Composites, Solvents?

  2. "TITER VALUE" ..Who, What, Where, Why and How?

  3. "SAMPLE SIZE" ..How much do I need or should I use? 

Learn more about Volumetric Karl Fischer Titration

Although these 3 areas at first may seem problematic and unrelated they are not.  In this 9-minute presentation we will explain why the burette size matters, how to calculate a correct sample size and explain how the volumetric titrator reagent strengths work.  Tying all three areas together will hopefully not only clear up some of the mysteries surrounding Volumetric Karl Fischer Titration but also empower operators with choices for conducting tests under varied conditions.  And, oh yes, obtain accurate and repeatable results every time.    Important note:1 ppm = 0.001 mg/g; 1 mg/g = 1000 ppm.

Created on 07/29/11 at 11:54:29

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