The System Health tests are also available using the command line interface (CLI). You can change the frequency and in some cases, thresholds.
The System Health tests are available in the Web UI under System Health -> Tests. This allows you to enable, disable, or get the status of the health tests. The tests are available from all menus in the Web UI.
These same tests are available from the command line (CLI) by logging in as root. You may also change the frequency of the tests. The capture_thresholds tests has maximums and minimums that can be set for each interface, the aggregate of all interfaces, and the default for the interfaces. The best place for more information is from the Help menus. Search for system_health and you will find a list of tests, their purpose, and how to change the frequency. There is also help on changing the thresholds of the capture_thresholds test.
The best method to understand the functionality of the tests and how to configure them is by using them, before they are needed.
More information can be found here: SCM System health