Quickmill Silvano PID Shows Temperature Drop While Pulling Shot

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GoGophers
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Joined: 11 years ago

#1: Post by GoGophers »

I'm brand new to this whole world, so I hope this isn't a stupid question.

Just bought a Vario and Silvano. Having fun experimenting, but I find that when I pull a shot with the Silvano, the PID starts at around 203 and drops throughout the pull.

Is this normal?

Thanks, Gary

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HB
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#2: Post by HB »

I haven't used the Silvano, but it's probably normal. I elaborated in Crossland CC1 excessive brew temperature drop during brewing:
HB wrote:Generally speaking, the boiler's PID readout is meaningless once the pump switches on because the probe may be intentionally mounted near the water inlet on the boiler to improve response time. However, the brewhead temperature should rise rapidly to the target brew temperature and then shouldn't drop much at all. Since you have a thermocouple/thermometer, snake the thermocouple wire up the portafilter spout and stuff the portafilter bowl with aluminum foil so the bead is pressed firmly against the dispersion screen. It's an imperfect measurement technique, but should be accurate within a few degrees to a Scace thermofilter reading.

Most espresso machines I've tested with a similar technique idled between 165°F and 185°F. The temperature should shoot up to the target brew temperature within 5-10 seconds, then fall off a few degrees. If you measure a 50°F drop at the brewhead in two ounces, then the boiler temperature is way off.
Any owners wish to confirm?
Dan Kehn

wsfarrell
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#3: Post by wsfarrell »

Not an owner (yet), but here's a link to a Vimeo video where Chris shows great temp stability during a "shot" with a Scace and a Fluke:

GoGophers (original poster)
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#4: Post by GoGophers (original poster) »

Outstanding! Exactly what I was looking for - thanks!

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HB
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#5: Post by HB »

Thanks for finding that video, it demonstrates my point: The boiler's PID readout is meaningless once the pump switches on. Notice how the PID readout starts at 200°F and plunges to 180°F and yet the brewhead temperature is stable.


Near final frame of above video
Dan Kehn