Not a member yet?
Click here to register.

Forgotten your password?
Request a new one here.

Shoutbox

You must login to post a message.

renatoa

12/05/2023 2:44 AM

Isdel7 and Sloppy Fingers

allenb

12/04/2023 11:51 AM

Ross

renatoa

12/04/2023 2:21 AM

, Rknjr17

allenb

12/03/2023 9:25 PM

zihyer

renatoa

12/03/2023 9:37 AM

M3Man and NHbrewer,

Shoutbox Archive

Forum Threads

Newest Threads

Skywalker, the ALM c...
Advice needed for ty...
Drum or Fluid Bed
My First Roaster (lo...
Wake Up Smart Home C...

Hottest Threads

Skywalker, the AL...	[62]
Larry Cotton's 'w...	[62]
1lb FB hopper roa...	[33]
Bellwether Roaster	[27]
Apwollo 11 roaste...	[27]

In Memory Of Ginny

Donations

Latest Donations
dmccallum - 10.00
JackH - 25.00
snwcmpr - 10.00
Anonymous - 2.00
Anonymous - 5.00

Users Online

Guests Online: 5

Members Online: 0

Total Members: 8,017
Newest Member: Isdel7

Oh no! Where's the JavaScript?
Your Web browser does not have JavaScript enabled or does not support JavaScript. Please enable JavaScript on your Web browser to properly view this Web site,
or upgrade to a Web browser that does support JavaScript; Firefox, Safari, Opera, Chrome or a version of Internet Explorer newer then version 6.

View Thread

Homeroasters - Home Roasting Coffee Community » ALL ABOUT ROASTERS » HotTop Roaster

Who is here? 1 guest(s)

Bean Temp Accuracy
Harlen	#1 Posted on 11/07/2023 10:43 AM
Newbie Posts: 2 Joined: January 17, 2017	How accurate is the bean temp in the 2K+ roaster?


renatoa	#2 Posted on 11/08/2023 12:00 PM
Administrator Posts: 2744 Joined: September 30, 2016	Bean temp measurement in a roaster is an idealization of a random mix of hot air and beans measurement, with hot air having at least 20 C degrees more than the beans. Given the fact that the beans to probe contact is very random, short time, and punctual, in a very small area, the main measurement value comes rather from the thin layer of air surround each bean, than from bean surface itself. If very different from the scenario where you immerse same probe in a liquid, read a very precise temperature and you can be confident it is what you read. Fortunately, in a roasting process, the factor of interest is the temperature differential rate of change, rather than the temperature itself. Because the randomness affects similarly both values used to perform the differential, the result could be more accurate than expected. In roasting literature you will find this differential called Rate of Change, or rather Rate of Rise (RoR) If your measurement has a single decimal precision/resolution, and requirement is to read the differential with half degree precision, you should average all readings in a 12 seconds window. For example, if you have a reading at a moment t, then other reading at t+12, and make the difference, you can be sure that the value of difference you compute, say 10 degrees per minute, statistically is almost sure somewhere in the interval between 9.50 and 10.50 degrees. Roasting applications makes multiple readings permanently, at least at second interval, and perform various average algorithms (filters), like Savitzky-Golay filter, to increase the precision of this difference, and compute it faster than a simply difference averaging.


Spyderman24-7	#3 Posted on 11/08/2023 2:26 PM
Newbie Posts: 19 Joined: January 15, 2019	Dunno about drum types, but in my sifter setup I get great feedback with a flexible probe submerged in the bean mass and real time readings consistently.


renatoa	#4 Posted on 11/09/2023 3:23 AM
Administrator Posts: 2744 Joined: September 30, 2016	This is the ideal case, probe submerged in a relatively slow moving pile of beans, with least airflow possible. But this contradicts the Sivetz roasting mantra: keep the beans moving ! In a commercial roaster drum the goal is to have as much of beans levitating, and as little as possible touching the wall. Think to grain threshing ;) This is done by a combination of carefully chosen rotation speed, together with the vanes design.

Jump to Forum:

Similar Threads

Thread	Forum	Replies	Last Post
Measuring Bean Temp in a Fluidbed	Fluidbed Roaster	11	11/09/2023 3:33 AM
Possibly the best alternative to a perforated plate for bean retaining	Fluidbed Roaster	3	07/30/2023 6:54 AM
Bean roasting times and color	Roasting Coffee	2	05/25/2023 12:40 PM
Replacement Solenoid for Bean Eject	HotTop Roaster	1	01/05/2023 4:58 AM
Artisan drop temp not right	Roasting Profiles	4	12/15/2022 1:35 AM