I haven't yet done a calibration procedure, but is the above linked procedure not valid for some reason? I'd like to have my results comparable to others, however I'm not planning to get any more lab equipment to do it as I feel others wouldn't be doing the same thing if the procedure is too convoluted.

I gathered some data this morning just to get an idea of the curve, the flow of this thing is pretty fast...maybe for a lever it has a lot more flow? I thought it was supposed to come calibrated, but maybe I'll try to reduce the flow down to a more normal range. This one is with less than 30 seconds of both filling the cylinder and the shot. Cylinder was empty before the graph stops, and temp started with a pre-heated Scace, that I removed for about 20s before locking in (temp starts climbing) then filled. Trying to simulate about what I would do for an actual shot, but maybe all that really matters is temp when there's flow.



The peak of this graph was 213.2F, and my "calculated" output was 211.8F. This was at 240F TB temp. I did a few more runs here then dropped down to 225F TB and got a 205F Scace. Then went down to 220 and pulled a very nice medium-dark roast Yemen shot.

I think boiling distilled water is the most practical way for me to calibrate all my probes to each other. Once I do that I'll work on the formula to determine what will track the Scace peak temp the best.

The procedure you linked is how you test the Scace but you do need to figure out the correct boiling temp for your elevation & pressure. Remember that you need to stop the flow while the group is filling. I put on an oven mitt & hold a wet cloth over the Scace outlet until I raise the lever.

Makes sense, I'll go with the local pressure from a local airport reading as that was suggested by Greg.

Should I mess with the output valve on the Scace? Once I let go of the lever it's only about 15s or so to empty the cylinder

I don't believe you can adjust the output unless you change the fitting. Just checked mine & it's 18 seconds until the lever hits the end of the stroke & 26 seconds until the chamber fully empties.

EspressoForge wrote:I haven't yet done a calibration procedure, ... I think boiling distilled water is the most practical way for me to calibrate all my probes to each other. Once I do that I'll work on the formula to determine what will track the Scace peak temp the best.

I would agree that just boiling distilled water will give you an accurate boiling temperature for your local pressure. There will be considerably less hard to deal with math as well. This works best if you happen to have a high accuracy photographic chemical thermometer available or a good candy thermometer as either should get you within 1 degree which is close enough. once you have that temperature of boiling distilled water look up the associated saturation pressure for that temperature and now you have the number to compensate between absolute and gauge pressure. Adjusting the thermocouple readings is also now straight forward.

On my lever with the thermofilter, I find that flow rate is the most critical factor in affecting measured temp. If I let it go on its own, it reads a couple degree higher. If it stops flowing, the temp will start dropping drastically. So your temp is probably in the right range.

You can retard the lever to maintain roughly the flow rate. I actually found that sneaking in a bare thermocouple over the basket during an actual brew is more accurate. But it wears out the probe and gasket... the other alternative is to build your own with variable flow rate, like what Rick Bond did.

https://m.youtube.com/watch?v=tJDc9BLl_5M

JohnB. wrote:I don't believe you can adjust the output unless you change the fitting. Just checked mine & it's 18 seconds until the lever hits the end of the stroke & 26 seconds until the chamber fully empties.

It looked like it could be tightened, but I'll leave it alone as it's probably standard. I'll check, but I'm guessing it's about the same as yours so better to keep it the same.

samuellaw178 wrote:On my lever with the thermofilter, I find that flow rate is the most critical factor in affecting measured temp. If I let it go on its own, it reads a couple degree higher. If it stops flowing, the temp will start dropping drastically. So your temp is probably in the right range.

You can retard the lever to maintain roughly the flow rate. I actually found that sneaking in a bare thermocouple over the basket during an actual brew is more accurate. But it wears out the probe and gasket... the other alternative is to build your own with variable flow rate, like what Rick Bond did.

https://m.youtube.com/watch?v=tJDc9BLl_5M

Was hoping the Scace would be my magic silver bullet!

Still need to calibrate my Scace. In the meantime here's a video of a long extraction showing off what the needle valve can do. Once the pre-infusion pressure was back up to 2 bar, I released the lever. Sorry about it being in portrait (and no sound) but for now it was the best I could do. Taste of this Gedeo Worka shot was excellent!

Very cool! You could almost fit a 30 oz tall cup there.

Yeah, it's pretty tall, I haven't yet finalized the dimensions or configuration. Once I do I think I'll get some kind of thicker drip tray etc. And move the group down a bit to compensate. Since it's been working very well, I just haven't had the time to do any reconfiguration!

I should get a bracket soon to hold the electronics box, after that I'll be deciding where the steam TB goes.

I've pretty much decided on this steam wand, unless anyone can find a different assembly that's better for around the same price:
https://www.espressocare.com/products/i ... team-valve

About the same as the silvia wand, but just a bit more polished. Both seem to have plenty of spare parts.