syrup draw-off temp variation using only a thermocouple

[English River Maple]

We have a thermocouple in the syrup pan which is connected to a digital read-out instead of using a dial thermometer. Does anyone know the best way to compensate for barometric pressure changes (barometer)accurately? Is the variation minimal enough where we won't have to compensate or worry about it? I guess we will know soon enough. We will use a hydrometer when we get close to drawing off, but the less we have to check, the easier it will be. I'm trying to get a jump on things so we can reduce the amount of unneeded surprises. Thanks in advance for any info.

[Tweegs]

The easiest way I can think of is to mount a second thermocouple in your flue pan.
The flue pan should be at 212 +/- depending on barometric pressure, even if you are running an RO I would think.

Periodically check the flue pan temp throughout the day, that will give you your offset.

Edit in: Of course, this assumes both thermocouples are reading the same. Depending on the type and manufacturer the tolerance could be as much as 1/10 degree F.

Easy to confirm though. Stick both probes in a pan of boiling water in roughly the same spot, note any discrepancy between the two and use the difference as a correction factor.

It won’t matter if the probes are reading the actual temperature dead nuts accurate, what you are interested in is the difference in temperature between the two probes, corrected.

[English River Maple]

The easiest way I can think of is to mount a second thermocouple in your flue pan.
The flue pan should be at 212 +/- depending on barometric pressure, even if you are running an RO I would think.

Periodically check the flue pan temp throughout the day, that will give you your offset.

Edit in: Of course, this assumes both thermocouples are reading the same. Depending on the type and manufacturer the tolerance could be as much as 1/10 degree F.

Easy to confirm though. Stick both probes in a pan of boiling water in roughly the same spot, note any discrepancy between the two and use the difference as a correction factor.

It won’t matter if the probes are reading the actual temperature dead nuts accurate, what you are interested in is the difference in temperature between the two probes, corrected.3

Thanks for your input, very helpful. Some really good ideas. Our thermocouple readout for the syrup pan is to 1/10 degree, we have another in the chimney above the base stack that is accurate to 1 degree. You are right, all we should be concerned with is the temperature reading of exactly 7 degrees above boiling of raw sap or water etc.

Thanks again for your input and ideas and good luck this season.