Hanna Checker

[abbott]

Ok, so I just tried my new Hanna Checker HI759 today. I've got some concerns. I was making syrup near the Dark/Very Dark line. One sample that I had graded visually as being really close to the line came out at about 36% (clearly dark) and another I thought was clearly very dark was reading at 24% (pretty much right on the line). Multiple tests varied a bit, but I was not being very careful about bubbles or wiping the cuvette, so I'm not very worried about that.

I got to thinking... light transmittance depends on the thickness of the medium that you are testing. As far as I know, the standards don't specify the thinkness of the syrup to be tested. Is it possible that looking at a sample in a VT Temp. Grade Kit will give a darker result than testing with the Hanna Checker, since the checker has a smaller sample bottle? Its definitely worth noting that this effect would show up more in darker samples and I admit that I haven't tested anything lighter yet.

I really like this concept, which would be far more accurate and reliable than the VT Grade Kits. I've never really trusted those, since they seem to be somewhat variable from year to year anyway. I know a lot of you have these things... what are your impressions?

There is a long discussion on this at sugarbush.info (http://www.sugarbush.info/forums/boiling-testing-filtering-bottling/4270-hanna-hi759.html) but it's mostly about the lovely lavender color of the tester, so...

[ryebrye]

I have one. The guys at the sugarhouse refer to it as my "lady shaver" due to the size and color.

The thickness of the curvette shouldn't matter for the light transmittance measurement because it takes that into account.

The grading kit would look a lot lighter if you took the samples out and dumped them into smaller containers but they would still be the same grades.

[Moser's Maple]

If you would keep reading the thread on sugarbush.info you'd see people are posting their results now

[abbott]

If you would keep reading the thread on sugarbush.info you'd see people are posting their results now

Read the whole thing. Didn't answer my question. And besides, MapleTrader is better so I though people should post results here. Only went to the sugarbush thread based on your link in an earlier MapleTrader thread. So... what did you find for results with your Hanna Checker?

I plan on opening up my VT grade kit at the end of the season and sampling that with the Hanna. Has anyone done that yet?

[abbott]

I have one. The guys at the sugarhouse refer to it as my "lady shaver" due to the size and color.

The thickness of the curvette shouldn't matter for the light transmittance measurement because it takes that into account.

The grading kit would look a lot lighter if you took the samples out and dumped them into smaller containers but they would still be the same grades.

From what I remember from my physics day, light transmittance is a ratio of light passing through to incident light. Which is thickness dependent, is it not? We can all see that just by looking at different bottles of the same syrup. I completely understand that the grade shouldn't be thickness dependent, which is why the grade would need to be light transmittance through a given thickness of syrup. I've never heard it defined that way, which is why this issue has me stumped.

[Moser's Maple]

Read the whole thing. Didn't answer my question. And besides, MapleTrader is better so I though people should post results here.

this is your opinion and I respect that, but I have found that both sites have valuable information and each one tends to lean towards different areas of specialties. Now the not so adult side wants to say if trader is so much better then why are ripping off a thread that was originally started on the inferior sugarbush.info.



I found the Hanna checked to be accurate with samples that visually could be looked at for grade termination. Once I trusted that is was measuring color in its respective grade I then moved onto the marginal colors to determine the color. I would then taste the syrup and make my decision by color and taste of what category the syrup fell into. NY has the new grading standards so we not only go by color, but taste is also determining factor of what is "proper grade".

[\quote]I plan on opening up my VT grade kit at the end of the season and sampling that with the Hanna. Has anyone done that yet?[/QUOTE]


As stated before since grade is more than just color but taste also; I have no plans of opening mytemporary grading kit. As mentioned on the sugarbush.info link. I found more consistent results when culverts were finger print free, free of air bubbles, and when the Hanna checker was held upright. I have also found it very handy to be able to put a light transparency number on the barrel along with date it was made, and the level of invert sugar for confections.

[relseek]

I agree with you Moser about being able to put a number on the jugs. It helps me a lot with those customers that want really dark as apposed to the "dark" that was just over the line from Amber.

[maple flats]

"I plan on opening up my VT grade kit at the end of the season and sampling that with the Hanna. Has anyone done that yet?" Quote from abbott.
While that might be entertaining, it may not answer many questions. The Vt. Temporary test kit is very Temporary. That is why they have a expiry date. The samples are the darkest each grade can be and still be labeled as such, but they keep gradually changing as they age.
As far as the Hanna Grader meter, the sample cuvette is made specifically to be used with that meter. It is measuring the % of light passing thru the sample. It will be accurate only if you follow the specific instructions, the cuvette must be perfectly clean inside and out, it must be totally dry before filling, it must be filled to the line exactly and you must hold it upright. Then the programming will tell you what % of the light is passing thru. I like it because it removes any doubt, there is no guessing if it is lighter or darker than the sample in the test kit.

[mellondome]

The tester is only for syrup, which should always be the same density. Density (specific gravity )is how a hydrometer works.

[abbott]

The tester is only for syrup, which should always be the same density. Density (specific gravity )is how a hydrometer works.

The tester is calibrated with glycerol, so I would assume that it would have no trouble reading the light transmittance of the burnt sugar & glycerol in the VT kits.

The purpose of testing the kit is to see if my eyesight is off or if the kit is off. If the kit tests at 25%ish for the Dark sample then I know that the VT kit and my Hanna agree. If the Dark sample is at, say, 36% then either the VT kit or my Hanna is off and I need to figure out which. The VT kits do lighten over time, but theoretically it should still be pretty close at this point.

It could be that the simple answer is that I have a defective meter. Or that the reddish tint to my syrup causes me to visually grade it lower than I should. Just trying to figure out which.

[abbott]

Ok, so I just had a long conversation with Matt at Hanna Instruments who was involved in the development of the Syrup Tester. Lets see how much of this I can get written while I remember.

Maple syrup should be graded using a path length of 10mm through a square cuvette using light at 560 nm wavelength. As compared to a glycerol sample. This according to USDA standards, which can be found here: https://www.ams.usda.gov/sites/default/files/media/MapleSyrupStandards.pdf

The Hanna tester uses a cylindrical cuvette with a longer path length, so the actual light transmittance detected is converted to account for the differences before the result is displayed on the screen. In other words, the actual light transmittance as seen through a VT temp. kit is way lower than the grading standards since you are looking through a couple centimeters of syrup rather than 10mm. But the samples in the kit are also calibrated accordingly. Hanna doesn't include all of this on their instruction manual to keep it simple.

The Hanna folks tried calibrating with water, but found that water was too temperature sensitive. They do not recommend opening and testing the VT temp kit as the matrix of the sample would differ and not necessarily provide results corresponding to a visual interpretation. I'll probably do it anyway, because why not? The kit is useless after the season anyway.

The kits only have 4% accuracy... so that's basically the room you have to make a judgement call on what grade to call a borderline sample.

We concluded that the reddish tint found in my syrup was likely causing me to interpret the color as being darker than it actually is... possibly combining with a Vt temp sample that is somewhat lighter than it should be.

As a bit of a side note, I have heard some folks say that you need to take flavor into account under the new grading system. After reading the USDA standards, that does not appear to be the case. It clearly states, "The color class of maple syrup is determined by... (t)he percent of light transmission through the syrup..." However, it is also notes that in order to be grade A, the syrup must "(Possess) a good maple flavor (taste) characteristic of the color."

Even using the Hanna meter (with its 4% accuracy) there is enough of a fudge factor that I will plan on using flavor to grade borderline lots.

Hope someone finds this helpful! If I get a chance to take some good pictures of my samples I'll post them.

[markcasper]

If these are only 4% accurate, why would anyone buy one??

[wiam]

If these are only 4% accurate, why would anyone buy one??
They are within 4% light transmission. Not 4% accurate.

[markcasper]

The kits only have 4% accuracy... so that's basically the room you have to make a judgement call on what grade to call a borderline sample.


I guess one of us, or both, misunderstood.

Would one buy this one, or the 350 plus dollar permanent ones? Will the USDA be coming out with a permanent grade set like my old one?? This is what sucks,the IMSI, the government tells us this is the way its going to be, will be prosecuted if its misgraded, but leaves us in the dark without a grader or an approved one, unaffordable as well.

[NH Maplemaker]

I used the checker all last season and when the maple inspector came in the spring she said everything checked out good! She then asked me How I graded the syrup? I told her that this year I used the checker ! She replied that her boss had order bunch of them for all the inspectors but they hadn't arrived them yet ! she asked if she could look at it as she had never seen one. She did a few comparisons with it using her equipment and the checker and when she was done said "this is great, can't wait to get one everything fell with in the grades just fine" I didn't tell her that we had also double checked everything with the new USDA permanent grade set!
So if New Hampshire maple inspectors are going to use them as one of there tools, Then it's good for me !

[markcasper]

I didn't tell her that we had also double checked everything with the new USDA permanent grade set!
So if New Hampshire maple inspectors are going to use them as one of there tools, Then it's good for me !

Let me get this straight......the USDA has a new permanent set with the new grade names? Where do I find out about this? As mentioned before, WIS. now has decided that grading be mandatory, but they have failed to tell us what we should use to grade, or what type or style is allowed. For Hanna to come out and manufacture a grader without having government approval was a huge risk on their part IMO.

[NH Maplemaker]

Ok, let me back- up a little bit! what I doubled checked with is the Lovibond Grading Comparator that has the new USDA international standard wheel ! I believe your right, USDA hasn't come out with a permanent grade set as of yet! Lovibond is what Leader and Bascoms are selling! Yes, they are not cheap $325.00 plus shipping!

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[markcasper]

Ok, let me back- up a little bit! what I doubled checked with is the Lovibond Grading Comparator that has the new USDA international standard wheel ! I believe your right, USDA hasn't come out with a permanent grade set as of yet! Lovibond is what Leader and Bascoms are selling! Yes, they are not cheap $325.00 plus shipping!
Have you heard whether the USDA will be manufacturing their own??? I would go with a Hanna, but during the season when things get messy an old time USDA comparer would seem to be the best choice and the fastest and easiest. The hanna would work good if you have a labratory, but having to have it completely cleaned for it to be accurate kind of scares me, along with keeping hard water spots and scratches off it. Since this is international, maybe Canada will be coming out with one?

[DrTimPerkins]

Have you heard whether the USDA will be manufacturing their own???

I believe that the last time someone from UVM PMRC spoke with them (over a year ago), it was not on their list for the short-term future. Perhaps we can check with them again. The options are temporary kits (both Vermont and Quebec make them) -- cheap, but you should get a new one each year, electronic graders -- moderate in price, but have to take some care in using them, or permanent grading kits (Lovibond) -- very expensive.

[maple flats]

I use the Hanna and like it. I use distilled water to clean the cuvettes, but I have now ordered 25 new cuvettes so I will use a new clean one on each test, I just wipe the outside with a micro fiber cloth, then remove the cap and fill the cuvette to the fill line.
I use serial numbered labels on my containers and a log book which shows each batch and the Hanna meter result. While I haven't had any customers ask for specific darkness within a grade, I can get that info if requested simply by checking the serial number and checking in the log book. I won't be taking the time to display it on each container unless I start getting a few customers who ask.

[upsmapleman]

Correct me if I'm wrong. I have a Hanna which I use but hate to mess washing the vials all the time. Have a old lovi bond so thought I would just buy a new disk. Wrong. They changed the size of the vial you view thru so it would not be accurate. I still use my old one with this in mind. Golden and light didn't change so it would work to grade that category. All of med. falls into amber and all of grade b falls into dark robust. So only what grades grade a dark amber do I need to use the Hanna to see what way it goes, Amber or dark.

[wnybassman]

I received my new Hanna checker the day and was anxious to try it out on the very last sample I had in the temp. grading kit from my last bottling session. My syrup, like others here, gets rather red when it gets dark. Grading that is always a challenge. Anyway, my very last bottled syrup had a bit of red in it, and with my eyes I graded it Very Dark as it seemed a tad darker than the darkest sample. But I ran it through the Hanna checker and it came up 32% which is 7% away from the Very Dark criteria. I'm going to keep all my grades as is this year because I already made the call, but it makes me wonder about a couple batches that were just into the Robust range and if they were really Amber Rich.

I will definitely get a 25 pack of vials before next season too.

[Wanabe1972]

I bought 25 viles for 40 bucks. Use them once and there is no cleaning. i have been taping the sample to the 5 gallon syrup containers that i use so i know whats in it.

[Quebecguy]

The Hanna folks tried calibrating with water, but found that water was too temperature sensitive.

So the Hanna engineer is saying that cool water is a different colour than warm water? Yikes! What about warm syrup as opposed to cool syrup?
Not wanting to buy an expensive new wheel for my Lovibond Comparator I bought a new Hanna Checker Model HI759 just near the end of syrup production this past Spring. Besides, I like the idea of exact measurements. I find the Lovibond Comparator very subjective and my wife and I have often had disagreements about the grade of syrups when the colour is near the borderline of Extra Light and Light for example.
I was very pleased with the few measurements I did with the Hanna Checker before the end of the season but then, wanting to show off the new gadget to my crew and other friends, I left a sample in one of the little tubes (cuvettes) so I would be all prepared to demonstrate it when the occasion arose. The first occasion arose about a week after and the percentage of light transmittance had gone from 61 to the high fifties. I left the syrup in the little tube and measured it again on April 16th. This time it measured 52. I put some lighter syrup in another cuvette at that time and measured it to be 60. On May 1st I measured the same two samples again and got 46 and 61. On June 13th I got 45 and 62.
It seems that one sample is getting consistently darker while the other is getting just a bit lighter. I am now storing the samples in an upright position to ensure I don't cause any bubbles to get into the samples when putting them in the checker. I'm going to keep checking these samples to see what happens. I won't contact Hanna about this anomaly until I have some firmer data but I am wondering if any other members of this Forum have had similar experiences. I would appreciate any and all comments.

[DrTimPerkins]

As the syrup is exposed to air, it oxidizes and turns darker. Normal.

[Quebecguy]

Thanks for the quick reply. I should have mentioned that my syrup samples have been kept in the closed cuvettes in the closed case of the Checker i.e. not exposed to air and in the dark. The second sample is not getting darker.

[DrTimPerkins]

Are the lids sealed somehow? It takes very little opening to allow air in.

[Quebecguy]

To: Dr. Tim Perkins,

Once again thanks for the quick reply. I hadn't noticed before that you are one of the editors of the Maple Syrup Producers Manual so I'll take this opportunity to thank you very much for sharing your knowledge with the rest of us. My 1976 edition was a valuable reference for many years so when I heard of the 2006 version I bought a copy as soon as I could. I consider it my "Bible" for all things sugaring.
I think my cuvettes were shut tightly enough to prevent oxidation and I don't think the colour would darken so much so quickly by oxidation alone. I've been saving a bottle of what was very light syrup from 1981 sitting on a shelf in my house and by eye I would say it is still an Extra Light (now a Golden).
I think I will continue to monitor the situation and carry out further tests to make sure I am not creating bubbles or fingerprints etc. etc. I want to be able to depend on this Hanna Checker for accurate results and I don't have that feeling right now.
Has anybody else tried repetitive testing of the same syrup and achieved consistent results with the Hanna HI759?

[ldick]

I also had inconsistent results and contacted Hanna. I was told by Hanna that accuracy of their meter is +/- 4% so variations of this amount are to be expected.

[DrTimPerkins]

As with any type of instrument, there are errors inherent to the instrument, errors in measurement conditions, and errors due to human factors. Many times these errors are additive, so unless great care is taken, you may find your measurements can be quite different from time to time. Even when you take great care to limit the influence of conditions and human factors, the instrument errors can't be eliminated. Syrup color may lighten or darken depending upon storage. If any oxygen can get in (especially in some types of plastic jugs), the syrup will darken in time. If in glass or tin, syrup can actually lighten under the right conditions.

[Quebecguy]

I also had inconsistent results and contacted Hanna. I was told by Hanna that accuracy of their meter is +/- 4% so variations of this amount are to be expected.

Thanks for this information. I just looked at Hanna's web site and, as you say, they state a +/-4% accuracy. I've had my two sample cuvettes of syrup and the calibration cuvette sitting upright in a closed cupboard since July 10th and just took them out now for a series of measurements being careful to handle them just by the plastic caps not touching the glass etc. Sometimes the measurements are repetitive and sometimes they are +/- 4% i.e. one reading at 48% transmittance the next, seconds later, at 50%. I suppose these results are better than just eyeballing the syrup but I find them disappointingly inaccurate.

[Sugarbush Ridge]

In spite of the +/-4% accuracy. That is better than my eye sight. And if the syrup is in that borderline area call it the darker grade. Just tell people that darker grades have better flavor,,,,,, really the truth.

[DrTimPerkins]

I suppose these results are better than just eyeballing the syrup but I find them disappointingly inaccurate.

The alternative would be a spectrophotometer costing thousands (or tens of thousands) more.

[MapleMark753]

The checker, at plus or minus 4 percent accuracy is a decent tool, but not magic in my opinion. I haven't seen or read here about the following aspect so here goes..... If you read the specifications for the checker from Hanna, its accurate to +/- 4 percent at 25 degress C only. Thats 77 degrees F. if I remember right. Any other temperature is not mentioned, either for ambient temp, or sample temp. I think, but don't know, that accuracy would decrease, maybe dramatically, at temps above and below what Hanna mentions as optimal.
So whats its accuracy at say 40 degrees F ambient and 100 degrees sample? I think Hanna probably has the answers but I can't find any info. Would Matt from Hanna be willing to delve into this?

[Hanna Instruments]

Hi,

Shayla with Hanna Instruments here. I wanted to touch base regarding the questions surrounding the accuracy statements at different temperatures. The only temperature for which we have an accuracy statement for this checker is 25 degrees Celsius, which is a standard reference temperature. It is important to note that temperature will affect the amount of light being transmitted through the sample, as it affects the density of the sample. If the sample is warmer than 25 degree C, it can also cause condensation to form on the cuvette, further affecting the instrument's ability to read the transmittance. We recommend grading the sample when it is in its steady state (not cooling down nor warming up), as the transmittance will change as the temperature changes. So if you tested the syrup while hot, you might expect a change in transmittance when it cools and vice versa. If you are going to be testing at a temperature other than 25 degrees C, we recommend that you test all of your samples at this temperature, to maintain consistency, so that you are comparing apples to apples, and not apples to oranges. When taking any kind of scientific measurement, you should always try your best to minimize the inconsistencies in the process, so the results are comparable. If you do have any questions or concerns, I am always happy to elaborate further. Please feel free to contact me any time at sfranks@hannainst.com or 401-765-7500x 164. I hope this helps!

--Shayla Franks