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General equation for box prediction?
Posted: February 23rd, 2019, 8:23 pm
by waterlubber
I'm wondering if anyone has worked out an equation that allows for a general solution of box temperature prediction. I've found that T = a + e^(b + cx) where x is time and T is difference from room temperature closely fits my recorded data; however, a, b and c appear to be unpredictable for starting conditions (volume and starting temperature.) I'm wondering if anyone knows of a solution that works for various temperatures of a specific volume or similar equations.
Re: General equation for box prediction?
Posted: February 23rd, 2019, 8:58 pm
by MattChina
waterlubber wrote:I'm wondering if anyone has worked out an equation that allows for a general solution of box temperature prediction. I've found that T = a + e^(b + cx) where x is time and T is difference from room temperature closely fits my recorded data; however, a, b and c appear to be unpredictable for starting conditions (volume and starting temperature.) I'm wondering if anyone knows of a solution that works for various temperatures of a specific volume or similar equations.
if there was then whats the point of the event
Re: General equation for box prediction?
Posted: February 23rd, 2019, 9:04 pm
by CookiePie1
MattChina wrote:waterlubber wrote:I'm wondering if anyone has worked out an equation that allows for a general solution of box temperature prediction. I've found that T = a + e^(b + cx) where x is time and T is difference from room temperature closely fits my recorded data; however, a, b and c appear to be unpredictable for starting conditions (volume and starting temperature.) I'm wondering if anyone knows of a solution that works for various temperatures of a specific volume or similar equations.
if there was then whats the point of the event
As a general warning, DON'T rely on an equation. Bad idea; just do the trials. Invest your time in good results.
Re: General equation for box prediction?
Posted: February 24th, 2019, 8:20 am
by rohans415
You could always run multiple trials (multiple temps, different volumes) and create a regression formula via StatsCrunch or some other program.
Re: General equation for box prediction?
Posted: February 24th, 2019, 8:25 am
by JoeyC
Equations can never fully capture the essence of your device because it's not ideal, is always changing, and its surrounding factors are so many that a single equation cannot adapt effectively. I tend to just derive my k value of my device (via multiple trials over different temperatures and time spans) and then use that, trial data, and gut feelings to intuit what the final temperature will be.
Re: General equation for box prediction?
Posted: February 24th, 2019, 10:11 am
by TheChiScientist
JoeyC wrote:Equations can never fully capture the essence of your device because it's not ideal, is always changing, and its surrounding factors are so many that a single equation cannot adapt effectively. I tend to just derive my k value of my device (via multiple trials over different temperatures and time spans) and then use that, trial data, and gut feelings to intuit what the final temperature will be.
Note that there are always just too many variables to factor in. No simple equation would be capable of calculating temp accurately given all those variables. Only multiple tests of your device will provide an accurate estimation.
Re: General equation for box prediction?
Posted: March 7th, 2019, 10:56 am
by CPScienceDude
TheChiScientist wrote:JoeyC wrote:Equations can never fully capture the essence of your device because it's not ideal, is always changing, and its surrounding factors are so many that a single equation cannot adapt effectively. I tend to just derive my k value of my device (via multiple trials over different temperatures and time spans) and then use that, trial data, and gut feelings to intuit what the final temperature will be.
Note that there are always just too many variables to factor in. No simple equation would be capable of calculating temp accurately given all those variables. Only multiple tests of your device will provide an accurate estimation.
I use an equation and its never more than a 2 degrees off
Re: General equation for box prediction?
Posted: March 7th, 2019, 11:36 am
by JoeyC
Until your ESes use a broken thermometer.

Re: General equation for box prediction?
Posted: March 7th, 2019, 12:35 pm
by TheChiScientist
JoeyC wrote:Until your ESes use a broken thermometer.

That or they use a more calibrated and accurate thermometer than yours. Or the other way around...

Re: General equation for box prediction?
Posted: March 7th, 2019, 12:43 pm
by CPScienceDude
TheChiScientist wrote:JoeyC wrote:Until your ESes use a broken thermometer.

That or they use a more calibrated and accurate thermometer than yours. Or the other way around...

Wouldn't it make a difference no matter how you do your prediction?