Expobar Office

diagram

https://wiki.wholelattelove.com/images/f/f1/OFFICE_CONTROL_Parts_Diagram.pdf

Added thermosyphon restrictor for shorter flush times, pn 50020020

https://www.home-barista.com/tips/expobar-office-long-flush-times-t17803.html

Can change to this one

https://www.cafeparts.com/Ptfe-Flat-Gasket-%C3%98-18x3.5x1-mm/Product_Manu/13222/Expobar/50020000

Added EricS TC adapter to read group head temp

Calibrate my TC/meter. Based on the barametric pressure reading nearby at the time (29.99), I figured I was right at 212 boiling temp, and my meter read 204 when placed in a pot of boiling water/steam, so I correct by 8f.

Add pressure gauge

https://www.home-barista.com/espresso-machines/testing-brew-pressure-t153.html

Use one of these for the pressure gauge, so I can read it from ESP32

https://www.ebay.ca/itm/1-8NPT-Stainless-Steel-Pressure-Transducer-Sender-Sensor-0-4-5V-Oil-Fuel-Air-New/173131342041

https://www.aliexpress.com/item/32909715955.html

note 14 bar = 203 psi

Volts Bar

0.5 0

2.5 7

3.3 9.8

4.5 14

So at max esp32 GPIO voltage of 3.3, its about 10 bar

Pressurestat adjust

counterclockwise to raise temp

Access from front of unit, remove front cover under grouphead, yellow circular pressurestat, small phillips to adjust

Dec, 2023
was around 224-231 boiler temp

changed to 227-234

Picture with front cover (under head) removed. Yellow circle is pressurestat. Philips screw in center to adjust. Small adjust for deg or 2 change.