barometer conversion chart

[7810hunting]

I'm looking for a chart that shows the boiling point of water using a barometer
and your elevation site of sugar shack.

[DanE.]

This is the chart I use.

http://www.hi-tm.com/Documents/Calib-boil.html

works very well.

[Beweller]

The attachment sounds like it is telling us to correct the boiling point for elevation AND barometric pressure.

This is incorrect. The boiling point is NOT a function of elevation. The boiling point depends ONLY on pressure.

The use of elevation for boiling point correction uses elevation for an approximation of barometric pressure. Note that it is an approximation.

[wnybassman]

Wow, that chart makes my head hurt. But it seems to be right on, I'm at 1286 feet and water boils most of the time right at 210. Never checked it against a barometer, but average pressure always seems to be right around 29.8 to 30.0 inches a lot of the time (I'm a fisherman so I like to pay attention to barometric changes) I'll have to pay attention to the barometer this season and compare it to that chart.

[DanE.]

The attachment sounds like it is telling us to correct the boiling point for elevation AND barometric pressure.

This is incorrect. The boiling point is NOT a function of elevation. The boiling point depends ONLY on pressure.

The use of elevation for boiling point correction uses elevation for an approximation of barometric pressure. Note that it is an approximation.

It depends if the source of your pressure has been already been adjusted for sea level, which if you are getting it from the tv or online source like noaa, weather channel.

If you take that chart and use it up against any of the online calculators. it is actuate to a fraction of a degree.


Dane.

[Marcland]

Boiling point of water is directly linked to barometric pressure.
Barometric pressure takes into account elevation, so you just need to use a good barometer. Here is a simple MARCLAND baro/boil chart

[Dennis H.]

Very nice Marcland, Thanks. Simple is better.

Now I need to pick up a barometer.

[Bucket Head]

These conversion charts are nice, but you really need to go with the hydrometer and not rely on the barometer to determine when you will have syrup.

How many guy's out there have boiled to seven degrees over the boliling point of water and did'nt have syrup? I have, and it was more than frustrating at the time. Water usually boils here at around 210-ish, but at 217-ish, we would never have syrup. We have found that 219, nine degrees over boiling, not the "standard" seven degrees, is when we have syrup.

I don't know why this is, and I don't know how the "seven degrees over" came to be, but it is not always the case. I have a cabinet full of standard thermometers, digital thermometers, hydrometers, and new last year, an auto-drawoff unit. They can't all be wrong. Nine degrees over is our new standard.

Steve

[danno]

Steve - completely agree. I'm not at syrup until I hit 221 f. +/- very little and my elevation is only 340 and water boils here at about 212 - so 9 degrees over for me as well.

This is reading the temp with two differnt thermos (which read the same - 221), and checking density with two hydrometers. So unless both thermos are wrong or both hydros are wrong, it's 221 for me - but wish it was closer to 219.

[Bucket Head]

Danno,

I can't explain why we don't have syrup at the seven degrees over. Maybe Central N.Y. is the Bermuda Triangle of sugaring? All instruments start doing strange things and the readings make no sense, lol!!

Seriously, I hate it when someone asks "How do you know its syrup?" if they see me checking the temp. I hesitate to mention the nine degrees over because they may have heard or read about the seven degree thing. I feel like I'm going to confuse them if I try to explain. Nowadays its just easier pointing to the red line on the hydrometer and saying "its syrup when I can see that".

Steve

[Dave Y]

"I don't know why this is, and I don't know how the "seven degrees over" came to be, but it is not always the case. I have a cabinet full of standard thermometers, digital thermometers, hydrometers, and new last year, an auto-drawoff unit. They can't all be wrong. Nine degrees over is our new standard."

After read the article in the link that DanE provided I think all thermometers could be wrong!

[Flat Lander Sugaring]

In 08 I kept a log of when I drew off what the temp was, barometric pressure and time. I'll see if I can dig it up I was curious if it had anything to do with sugaring. Because some days it just seems that you boil forever before you make any syrup and nothing has changed except for the time and pressure.

[Bucket Head]

Air pressure, high or low, dry and sunny or wet and windy days, even the change from daytime/dusk/evening can alter boiling rates. Sometimes it seems like the level in the feed tank is'nt going down at all!

I'm curious about your temperatures also. Danno and myself can't be the only one's out there making syrup over the seven degrees the manual says is syrup temperature.

Steve

[3rdgen.maple]

BucketHead and Danno from a NYer to a couple others I have the same problem 9 degrees is the norm for me as well. I actually thought I was insane till I read this post. I even at times filled my finisher up with water and boiled it to check the boiling point with the thermometer from the evaporator, adjusted it and put it back in the evap and still went to about 9 over before I seen red on the hydrometer. At one point I bought another hydrometer and checked them to each other to make sure of their accuracy and still had the same results. I now have 4 hydrometers and one reads different than the others. I pretty much eliminated everything I could think of and my conclusion to this problem is this..... That the reason NY syrup is better than any other is because of this weird temperature difference lol.
Now with all that said If I was to keep up with barometric pressure and trying to determine the boiling point of water to get my finished syrup off the evaporator Id be wasting more time than I had just checking and calibrating every few minutes as things can change that fast. So skip all that and just buy a hydrometer and when you pull of your first batch look at the thermometer and see where the temps at and use that temp for a reference for the rest of the day and rely on the hydometer to get you where you need to be.