Which Fix n Fax reference pertains to the system test check procedure?

The reference to the system test check procedure in the Fix n Fax documentation is Fix n Fax 155. This reference specifically outlines the procedures and guidelines for conducting system test checks, which are critical for ensuring that all systems and equipment are functioning correctly and safely in a firefighting context.

In firefighting operations, understanding and following these procedures is essential for maintaining equipment reliability and operational readiness. The details provided in Fix n Fax 155 would include information on test protocols, necessary checks, and how to document findings, which ultimately supports the overall safety and effectiveness of firefighting efforts.

Other references, such as Fix n Fax 52, 52a, and 52c, while they may cover related topics or procedures, do not specifically pertain to the system test check procedure, which is why they are not the correct choice here.