We usually don’t find a full time scrum master. Scrum master is described by scrum guide as one who teaches, facilitates and removes impediments. When the team is relatively new it takes time and the team follows scrum religiously. This is when the team needs a scrum master who can teach scrum full time. Follow SBOK guide of http://www.scrumstudy.com which is a best book to understand Agile Project Management.
Organizations need to be assured the individuals that manage their projects can integrate methods to achieve sustainability goals and still achieve project specific objectives. Project Managers need credentials that validate their proficiency with these specialized qualities. PMP Certified and scrum certified project managers can learn, apply, and validate mastery of sustainability based project methods to meet these demands.
People who are involved and are performing all their activities very appropriately scrum guide can help them even in a better way because that help us a lot with understanding all the needs and growing which works.