Calibration problem

[bruerik]

I did the calibration like the instructions say for my mash tun, but it did not calculate the heat capacity. I entered the size of my pot with dimensions, volume of pot. Amount of water. Air temperature of the room, temp of water after heating, after 5 minutes and after 65 minutes. But it only calculated the Heat transfer coefficent. I never had time to do it before because of being busy even though I had the program a while.

Any help of what to do would be nice.

Thanks
Erik

[jeff]

I did the calibration like the instructions say for my mash tun, but it did not calculate the heat capacity. I entered the size of my pot with dimensions, volume of pot. Amount of water. Air temperature of the room, temp of water after heating, after 5 minutes and after 65 minutes. But it only calculated the Heat transfer coefficent. I never had time to do it before because of being busy even though I had the program a while.

Any help of what to do would be nice.

Thanks
Erik

What are your readings?

[bruerik]

Jeff,

Here is a screen shot of what I entered.

Erik

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[jeff]

Jeff,

Here is a screen shot of what I entered.

Erik

To determine vessel heat capacity, the vessel has to be at the ambient air temperature (Environment) when you add the infusion. The infusion water will cool as a result of coming in contact with the room temperature vessel. This change in temperature is measured after 5 minutes to allow time for thermal equilibrium to be achieved.

The example you provided shows the infusion temperature being the same as the temperature after 5 minutes. This means that the vessel had no effect on the infusion temperature; which means that the vessel effectively has zero heat capacity.

Next time you conduct the test, heat your test water in a vessel other than the vessel you are calibrating. Hope this helps!

[Bobby_M]

Well wait a second.. if you are heating your strike water in the mash vessel wouldn't a heat capacity of zero actually be accurate? In other words, you don't need to account for the mash vessel pulling heat from your strike water because it's already up to temp.

[jeff]

Well wait a second.. if you are heating your strike water in the mash vessel wouldn't a heat capacity of zero actually be accurate? In other words, you don't need to account for the mash vessel pulling heat from your strike water because it's already up to temp.

Yes, which is why you choose "None" for the heating vessel in the mash-in editor. The editor then assumes that the heat capacity of the vessel is combined with the heat capacity of the strike water. Even so, the vessel still has heat capacity whether it is accounted for as part of the grist heat capacity or the strike water heat capacity.

[Bobby_M]

Good point and thanks for the clarification. I suppose that method would account for situations where you heat your strike in the tun but also need to account for the temperature of infusions that enter later such as decoctions.