I have been experimenting with the Hottop B and have found that I can get reliable readings on the B without the "Shreddies" screen (see beginning of thread). On the B the contrast between the digits of the LED and the background is sufficient to provide reliable results without the screen to shield reflections.
A suitable screen is necessary to achieve reliable readings on the Hottop P and LCD multimeters.
Logging on the Hottop B without a screen to shield reflections:
This chart shows a comparison of Hottop P (magenta) and Hottop B (red) roasts both setup in exactly the same way! Both have the same 320 g charge of the same beans with the same program for fan and heater settings. Both reached first crack at the same time! The difference between them is partly due to the clogged rear filter on the B and partly due to the thermistors reading very different temperatures at the same point (FC) in the roast.
Log file chopped to show key stages. I clearly have not learned to tame the end of the roast in the B yet, it is very different from the P:
Log created at 12:20:13 09/09/2009
Use Options|show log template form to modify this template.
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Beans/Blend name: Cachoeira 320 g
Profile description: 100% power to 205 then 70% to FC + 60 secs then 20%
Roast notes:
Cupping results:
OCR Roast Logger by GreenBean TMC.
Roast started at 12:31:21 09/09/2009
Elapsed time , OCR 1 , OCR 2 , Event type
00:00,71, ,Beans loaded
00:05,71, ,timer
00:10,71, ,timer
00:15,72, ,timer
00:20,72, ,timer
00:25,73, ,timer
00:30,74, ,timer
00:35,75, ,timer
13:40,206, ,timer
13:40,206, ,First crack start
13:45,206, ,timer
15:45,212, ,timer
15:46,212, ,First crack end
15:50,213, ,timer
16:35,214, ,timer
16:38,214, ,Second crack start
16:40,214, ,timer
16:41,214, ,Beans ejected