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Showing results for tags 'thermocouple'.
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I received my Londinium 1 three weeks ago, and it is a beautifully crafted machine. I don't remember seeing any brew temperature data online, so I hooked up a Scace device and began testing. When the results were a little hard to understand, I temporarily strapped a second thermocouple to the outer surface of the group. This made the actual brew water temperature much easier to predict, since the superheated boiler water is cooled by the group before it hits the coffee bed. The procedure for Scace testing was as follows: 1. remove the portafilter from the group for ~30 sec to account for time spent dosing and tamping 2. reinsert the portafilter into the group 3. smoothly pull the lever to the full down position and allow 3 grams of water to pass through under boiler pressure only (simulating a short preinfusion) 4. smoothly raise the lever and allow the "extraction" to proceed under spring pressure until an additional 40 grams of water had come through 5. record initial and final group surface temperatures plus peak and final brew water temperatures Notes: a. The 3 grams and 40 grams of water are somewhat arbitrary values, but seemed to correspond with my actual shotmaking technique b. Per Londinium instructions, the tests were performed without any group flushes and at random intervals between shots c. Pressurestat was set to cut in at about 1.0 bar and cut out at about 1.2 bar. This corresponds to an average boiler temp of about 122C or 252F. Some of the data is summarized in the graphic below. Please excuse the Fahrenheit measurements; since I am in the US, those are the units I normally use. Comments: 1. These shots were measured over the course of several days at random times. Other than an open-group flush after the boiler first came up to pressure in the morning, I made no attempt to control group temperature. 2. There is a fairly linear relationship between initial group temp and average brew water temp. This makes group temp a good predictor of average brew water temp. 3. Brew water temp drops an average of about 10F (6C) during the course of a shot. 4. The most curious result was the "hole" in both group temp and the resulting brew water temp that you see on the graph. It seems that the thermosiphon "flips" at group temperatures between 183F and 190F (84C to 88C). In this group of 24 random measurements, no shots appeared in that range. A different pressurestat setting might shift this range up or down. 5. So far I've made only a limited number of direct taste comparisons between otherwise-identical shots prepared on the L1 vs my Speedster. Many of the L1 shots have compared favorably, but the Speedster shots have been more consistent. Looking at the data on the graph, this might be expected. 6. I would be very interested to see this type of data from other L1 users.
Am I missing something drastic here but if you sealed the top or the inside of the nut up with something like JB Weld is there any reason you couldn't use one of these as an alternative to Erics adapter? I know it's not pretty and it's not going to be a permanent solution but it would be close enough? https://www.amazon.co.uk/HiLetgo-Temperature-Sensor-Probes-Thermocouple/dp/B00M1PMEJW/ref=sr_1_2?ie=UTF8&qid=1477496743&sr=8-2&keywords=k+type+m6+thermocouple
Thought I might develop a roast profiling prog for PC (sure they exist, but where's the fun in that?) Anyway I'm mulling over getting one of these: http://www.ebay.co.uk/itm/K-Type-USB-Thermometer-Thermocouple-Sensor-Data-API-w-CD-for-PC-Laptop-Win-XP-7-/331669173502?hash=item4d3905f4fe:g:BfUAAOxyVaBSrD2P (USB-interface for a K-Type with included SW) Question is, would you trust the driver DLLs not to carry viruses?
After the success of my 'screw in' Pt100 sensor, for the Gaggia Classic and pre 2006 Silvia's - I'm now trying to produce a Pt100 sensor that is embedded within a surface mounted thermostat housing, as used on the post 2006 Silvias. Essentially it's going to be a direct replacement for the cylindrical thermostat, that's held in place with the metal strap - like this (this is a standard Silvia thermostat, NOT my sensor!). I don't own a Silvia, so am initially looking for someone that has one - that either already has fitted a PID (perhaps with a K or J thermocouple) and they want to upgrade to a Pt100 - or they're seriously thinking of fitting a PID in the very near future and needs a sensor - and they would be interested in helping me test the fit and function of this sensor in the Silvia... and in return they'd get it at a good price (£10 shipped). As soon as I have the first sensor ready, then I'll post a pic of it (not that it's very exciting) in the next day or two - but right now I'm looking for an initial beta-test user, and also would like to see if there are others that would be interested in these sensors? I'd envisage a proper production cost being slightly higher than my Gaggia sensor, at £18 shipped. Anyone interested in these - or interested in being a beta tester? Shades