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Support / Re: Behmor 1600: Where to place thermocouple(s)
« on: April 12, 2014, 08:43:25 PM »
There is really no convenient way to place a thermocouple in the Behmor 1600. If I were able to thread it into the rotating drum, I would still be concerned about the offset (influence) by proximity to the heaters.
What is possible, however, is to put a thermocouple in the exhaust duct at the top rear of the roaster.
If you have ever removed the exhaust duct (5 screws) you will see that the ventilation air is provided by a small fan. There is not much air being pushed through; just enough to keep the roast even and get rid of the moisture. The exhaust air measurement is in some way analogous to bean-mass temperature but you need to remember that there is a time-delay between the beans and the duct and another in the thermocouple assembly.
I roasted a nice Sumatra this afternoon. At the point where the second crack was about to begin, I went to cool. With no heat being applied and extra ventilation air, there was STILL a temperature spike of 40F. Roasts really go exothermic …!! There is real value to be able to see that spike. The next time I will watch for it and go to cool as soon as it begins.
Roastmaster's data-logging feature is great. I wonder if there is a way to keep that (manual) temperature graph recording …after... I stop the roast. I would love to do that to get the full shape of the spike.
Jerry
BTW, the type K thermocouple assembly is high-quality and low-cost and comes with a threaded end and matching nut. All I did was drill a 5/16 hole at the end of the exhaust duct. Look here:
http://www.ebay.ca/itm/Thermocouple-K-Type-Probe-Sensors-Connector-50mmL-/250983707501?pt=LH_DefaultDomain_2&hash=item3a6fcb736d
What is possible, however, is to put a thermocouple in the exhaust duct at the top rear of the roaster.
If you have ever removed the exhaust duct (5 screws) you will see that the ventilation air is provided by a small fan. There is not much air being pushed through; just enough to keep the roast even and get rid of the moisture. The exhaust air measurement is in some way analogous to bean-mass temperature but you need to remember that there is a time-delay between the beans and the duct and another in the thermocouple assembly.
I roasted a nice Sumatra this afternoon. At the point where the second crack was about to begin, I went to cool. With no heat being applied and extra ventilation air, there was STILL a temperature spike of 40F. Roasts really go exothermic …!! There is real value to be able to see that spike. The next time I will watch for it and go to cool as soon as it begins.
Roastmaster's data-logging feature is great. I wonder if there is a way to keep that (manual) temperature graph recording …after... I stop the roast. I would love to do that to get the full shape of the spike.
Jerry
BTW, the type K thermocouple assembly is high-quality and low-cost and comes with a threaded end and matching nut. All I did was drill a 5/16 hole at the end of the exhaust duct. Look here:
http://www.ebay.ca/itm/Thermocouple-K-Type-Probe-Sensors-Connector-50mmL-/250983707501?pt=LH_DefaultDomain_2&hash=item3a6fcb736d