A slight delay or minor difference between EM readings and a mechanical pressure gauge is expected and within normal operating tolerances.
Measurement accuracy and tolerance
Mechanical pressure gauge
Accuracy class: 2.5 (standard for coffee pressure gauges)
Measurement range: 0–12 bar
Tolerance: ±0.3 bar
BOOKOO EM
Measurement tolerance: ±0.1 bar
When combined, the maximum possible deviation between EM and a mechanical pressure gauge is ±0.4 bar. This range has been tested and is considered normal.
Is this considered a malfunction?
No.
If the pressure reading differs slightly from another brand’s gauge but extraction behavior and puck resistance remain within normal ranges, the system is operating correctly.
Differences may occur due to:
Different sensing principles (electronic vs. mechanical)
Response speed differences between devices.