1. Run Glances with the sensor plugin enabled: every 3 refreshs a peak of Glances process CPU is observed.
2. Run Glances with the sensor plugin disabled: no CPU peak observed.

Note: the peak every "3 refreshs" is related to the following key in the sensors code:

# Define the default refresh multiplicator
# Default value is 3 * Glances refresh time
# Can be overwritten by the refresh option in the sensors section of the glances.conf file
DEFAULT_REFRESH = 3

The goal is to understand why the CPU peak is so high (from 5% to 11% on my system).