Hi -

I have "designed" and have manufactured (for me) a custom fitting to take the place of the M6 x 8 allen-head screw found on E61 groupheads and on Silvia (others also). I have termed this fitting the "Thermocouple Adaptor", but it is also a "Thermometer Adaptor". The thermometer adaptor for E-61 machines is available only in stainless steel and will accept ONLY a 1/8" thermocouple (of your choice) or the modified digital thermometer I offer. It replaces the M6 allen-head screw by screwing into the grouphead and sealing with a copper washer exactly like the existing M6 screw in your grouphead. The 1/8" thermocouple or digital thermometer stem is sealed to the adaptor by means of replaceable nylon ferrules. No drilling, tapping, soldering, brazing, cutting, teflon tape, or epoxy are required. Installation instructions for the adaptor can be found on my crude FTP "website" in the file entitled "Adaptor06.pdf": http://users.rcn.com/erics/. Click on Adaptor06.pdf and save the file to your computer. Improved installation instructions for the most current digital thermometer can be found in the file labeled DigThermAdptr4.pdf. Please read these files carefully as they are designed to answer most questions concerning installation and use. You might also want to read the Adaptor Tidbits file as it also contains useful information.



The thermocouple/thermometer adaptor kit consists of the adaptor with copper washer, a spare copper washer, a spare nylon ferrule set, and a plug to seal the adaptor should you wish to or need to suspend temperature measurements. After inserting your thermocouple and attaching it to your appropriate meter, you can easily observe and/or record brew and/or flush water temperatures approximately 1.25" upstream of the espresso puck/empty basket using your normal espresso brewing/flushing practice. EQUALLY IMPORTANT, you will be measuring a temperature that is very representative of grouphead temperature.



OK, I want one, what do I do now? - Read the installation instructions, then read the installation instructions and finally read the installation instructions again appropriate for the adaptor kit you desire. Complete ordering, inventory, and pricing information can be found on my FTP site in the document entitled "Pricing_Inventory_Ordering". You need to be somewhat mechanically inclined and understand the use of thermocouples and appropriate temperature meters OR have a good friend who is. The adaptor kit prices, which INCLUDE a mandatory $15 donation to CoffeeKids but include shipping via USPS 1st Class are: Silvia/Custom (Brass) - $57, E-61 Thermocouple Adaptor - $68, Digital Thermometer with switchable degrees F/degrees C - $97.00. Shipping outside of the US (except for Canada) via USPS Priority Mail (small flat rate box - partially trackable) is $22 additional. Paypal is accepted for a small additional fee as fully described in the Pricing_Inventory_Ordering pdf document available here: http://users.rcn.com/erics/

COMMENTS/SUGGESTIONS on the instructions or questions of a general nature that could be included in the FAQ section of the install manuals would be GREATLY appreciated. Thus far, a total of fourteen hundred (1400) thermocouple adaptors and digital thermometer adaptors have been shipped to users of varying ability in Australia (38), Austria (1), Belgium (2), Canada (53), Czech Republic (1), Denmark (22), Dubai (1), England (12), Estonia (1), Finland (7), France (2), Germany (5), Greece (1), Guam (1), Hong Kong (5), Ireland (2), Israel (4), Japan (2), Mexico (1), Netherlands (26), New Zealand (4), Norway (4), Poland (5), Russia (2), Saudi Arabia (2), Singapore (5), Sweden (6), Switzerland (1) and, of course, the US (1184).

Stock Status:

E-61 (Stainless Steel) - 54
Silvia/Custom (Brass) - 3
Digital Thermometer in F/C - 57

THE 1400th ADAPTOR WAS SHIPPED TO AUSTRALIA

It is always best to check stock status BEFORE you place an order as this post is, maybe, edited on a monthly basis. Edited 05/24/2012 to reflect adaptors shipped and stock status. Thermometer construction has vastly improved. New thermometers are assembled without the use of any hot melt glue as the thermistor wiring (and thus the thermistor itself) is held in place with a wedged small brass or aluminum tapered tack. The lower housing of the thermometer has been machined slightly to allow for much easier assembly or user repair and the latest units include soft-touch buttons and auto-shutoff to extend battery life.



Acknowledgements:

Thanks to Andy S. for suggesting I go with an E61 adaptor vice just one for Silvia after my original post on AC and to Sean L. for suggesting nylon ferrules and to Greg S., Sean S., and Dave S. for devising all sorts of innovative methods of measuring brew water temps. I also thank Lino V. for his unselfish OK to use several of his E61 group drawings contained in the thermocouple adaptor, digital thermometer, and adaptor tidbits documents.

The original posting in March of 2006 was cross-posted in its entirety to AC and CG.

Eric S.
erics@erols.com

Greg milled his Astra to insert a temperature probe (discussion), Dave detailed a low-cost alternative in No More Guesswork! Naked Truth of E61 Temperature Revealed, Sean fabricated his own adapter as documented in Thermal Obsession...

... and now Eric has kindly done all the legwork to bring us a ready-made package:


E61 adapter with 1/16" sheathed thermocouple

Although I've been on respite from "gadgets" as part of my study of holistic barista techniques, the attraction of his offer was irresistable - I e-mailed Eric the same hour that I read his post. The adapter arrived last week and I installed it over the weekend:



Eric's instructions are thorough and packed with well-drawn diagrams. However, in my excitement to get it installed, I initially didn't insert the probe at the depth shown above, but rather near the bottom of the hole, directly into the valve chamber. Needless to say, the temperature measurements fluctuate dramatically in that location. Moving it closer to the location Eric suggests does produce more steady readings, but I'm intrigued by how accurately the sound of the "water dance" predicts the chamber temperature.

For HX owners who want to end their uncertainty about the proper cooling flush, this adapter / thermocouple combo looks very, very promising.

Yes, the adapter is installed on the Vetrano.

I plan to post temperature graphs reported by the thermofilter and adapter at different depths. For now, I'm evaluating it purely as an aid to managing the cooling flush. As my first test, I positioned the probe at the bottom in the valve chamber and followed my usual routine to see (a) what it read, and (b) if the end-of-dance technique was consistent shot-to-shot. The readings confirmed what we've said all along - nailing the temperature accurately based on sound is easy, especially if the shot interval is a few minutes minutes apart. At shorter, irregular intervals, it's difficult to judge with precision. That's where I am assuming the adapter's readings will prove most helpful.

Hello Everybody -

I operate a PID'ed Silvia and observe "grouphead" temperatures via a Type T thermocouple and the thermocouple adaptor. I read the temps on an Omega HH506RA and am continually amazed at the grouphead's behavior from a temperature standpoint.

Silvia's performance is documented here: http://users.rcn.com/erics/ under temperature graphs and also in the FAQ section of the installation manual available in the folder entitled "thermocouple adaptor".

For now I make only Cappy's but they approach and, if I am patient, meet the quality of those served at Murky here in DC. For me, that's saying a lot because Murky is truly top quality.

Eric S.

The wife was out for the evening, so I ran a series of thermofilter tests using the TC adapter to judge the correct flush. In other words, I want to answer the question: Assuming one forgets about observing the water dance or listening for HX sputtering, how consistent are the brew temperatures if one just flushes until the meter says temperature X followed by rebound Y?

I had already determined that the proper temperature at the well depth for my routine (flush... rebound 30 seconds... pull) was 206F. Keep in mind that for the purposes of this test, I don't worry about what the adapter temperature relative to the brew temperature might be, as long as it indicates the same readings every time. I postulated that since we're really tuning the flush, it's better to read the temperature BEFORE it's attenuated too much by the group, so I placed the probe at the bottom of the well. As I reported earlier, the reading is changing quickly at the bottom, but that's reality. I see a very distinct "knee" right around 205F. The temperature moves slowly prior to that and then plummets just past it. For this particular machine, my assumption is that it marks the end of the HX over-temp water exiting.

The series was proceeded by a "warm up" flush (flush... wait a couple minutes... begin series). Preamble out of the way, below is my Friday evening results:


Irregular pulls (3m, 1m30, 3m, 15m, in no particular order)

Some observations:

• Grouphead is definitely cooler and the HX hotter after the machine is idle for a long period (see line in red; rises more slowly at first, spikes higher)
• "Warm up" flush would spike well above the target brew range then settle down (this "high hump" profile was not recorded)
• Adapter feedback made it easy to stay within 1F, although occasional outliers still occur, especially if interval was short (see blue dashed line with 200.4F peak temperature)
• The adapter reading and thermofilter reading converge about midway into the shot; the thermofilter indicates a very slow decent towards the end and the adapter is reporting near flatline temperature from the HX (I did not show both readings on the chart above for simplicity).

The utility of Eric's adapter is plainly evident to me: By tuning the flush amount based on the adapter's TC reading, reproducible temperatures are easily obtained within ~1F. I wonder how well this holds up with the lowest-cost setup (approx. $20 digital thermometer + type K thermocouple) in place of my pricey rig (Fluke 54-II + special limits of error type T thermocouple).

Hi John -

These thangs require a thermocouple other than what (I believe) you have with the TM-125 and I suspect that the read rate of the TM-125 may be highly filtered and not readily adjustable. Does the TM have a standard thermocouple connection or a miniature one? Another good choice for a meter is one of the inexpensive Ebay 1/32 DIN PID's from Auber or ColdFusion, i.e. SYL1512 or TET-7100 - essentially identical.

Eric S.