Artisan Command for setting Symb ET/BT

[hermetheuscoffee]

I have come across a scenario that would really benefit from having an Artisan Command for settings symbolic ET/BT. In doing a 2-day test on a new 7-lb fluid bed roaster design, first crack is consistently happening at 400 degrees F, which is great!
However, when doing a sample-batch size (200g), both first crack and second crack are consistently happening at an indicated 17 degrees cooler. (i.e. showing ~383 degrees at first crack on the same bean.)
Because this is an automated PID-controlled roaster, I have created an Artisan button that loads VASTLY different PID settings for the tiny 200g batch (and that works perfectly!). I would love it if I could also control the Symbolic ET/BT value so that I could also apply a temperature probe correction for this tiny batch size.
Or is there perhaps another creative way to set the Symb ET/BT value by a button that I haven't thought of yet?

[MAKOMO]

It does not feel right to change the symbolic formula via an action dynamically. I would rather suggest to make the symbolic formula more intelligent using the just introduced symbolic variable WEIGHTin which holds the batch size in g as set in the Roast Properties. Would that be an idea?

[hermetheuscoffee]

I thought the new WEIGHT variable would be a great option, but in doing a number of tests, it doesn't work for my application. What I found was that when the bean mass is small enough to not even reach the thermocouple, the probe essentially measures the air temp (ET). But if you add just enough beans to cover the probe (say, 400g) it now accurately tracks the actual BT. Whether you have 400g or 4,000g. There's basically a threshold that is crossed (beans touching or not touching the probe), and based on that one threshold, I need to use one of 2 different Symbolic equations. So if there was some IF/ELSE logic that could be used in the SymbET/BT, this could work.... Something along the logical lines of:
IF (WEIGHT<400 Y21.1) ELSE (Y20.95)

[MAKOMO]

Well, there is some kind of IF/ELSE logic. Search for "Conditional" in the post Symbolic Formulas: Basics, New Variables and Applications

[hermetheuscoffee]

If I understand you correctly, you're politely telling me to RTFM. :D Sometimes I don't need a new feature. I just need to do a better job of reading what's out there. It LOOKS like this should work for me, and I'll test it out this evening. Thanks for this suggesion!

[hermetheuscoffee]

Marko, this works BEAUTIFULLY! Bravo and thank you! For others who might be interested in this function, I use this as my Symbolic ET/BT:
(Y2*1.11 if WEIGHTin<300 else Y2)

If less than 300g of beans are in the hopper, it "corrects" for the temperature probe discrepancy by a factor of 1.11. If 300 or more grams are added, it uses the BT reading unaltered.
It's interesting and very helpful that you can enter your bean weight in any scale (grams, pounds, etc.) and it converts that to grams for the purposes of this calculation.