3 Teams, to which Board does the Scrum Master belong?

I am now a Junior Scrum Master of three teams. 

I'd suggest that in Scrum there is no such role as "Junior Scrum Master" at all. It's rather more likely that there is a lack of agile maturity on the part of the company.

when they see the effort maybe of a fulltime scrum master, maybe this will change.

Perhaps they ought to be gauging outcomes, rather than effort. Might this be something you can help them with, as part of the Scrum Master's service you provide to the organization?

So to be clear, no tasks on the board for the scrum master?

Hi Adnan,

What does "board" mean for you in your context? 

When I hear board, I assume you mean a Scrum board of some sort. A way of making the work of the Sprint transparent (an information radiator) so Developers can visually track progress towards the current Sprint Goal. Example: Sprint Goal, Sprint backlog and some states to illustrate progress and impediments. 

Regarding "no tasks on the board for the Scrum Master?"...it really depends. If you are also one of the Developers on these teams and contributing to building the Increment(s) for the Sprint Goal, you would be helping with the Sprint backlog which would be on the board. If you are not one of the Developers, and the work you are describing does not align to the Sprint Goal/increment I would say it would not be on the board.

I would consider other options for making your work transparent if that is something you company requires.

The board is for the Development Team to track their work and progress towards the Sprint Goal. If you are doing work on that effort, then you would be considered a Developer and your work would be reflected on the board.  However as a Scrum Master for 3 teams, I find it highly unlikely that you will be doing work on the increment.  

If you read the Scrum Guide's section that describes the Scrum Master role, you will notice that there is no mention of work done for the increment.  Your work is focused on making the Product Owner and Developers more capable of producing valuable work that furthers the product.  

If your company wants to know what you are doing they should look at the productivity achieved by the Developers and Product Owner.  They should look at how capable the teams are at producing valuable increments of work that, when delivered, makes the end users want to use the product.  They should look at how the work being done by the Scrum Teams are enabling Sales to bring more customers to the product.  

From what you say about your company, I am not sure that they will accept this so you need to find another way to show them the work you are doing.  Don't use the team's boards as that will dilute the value of the Product and Sprint Backlogs. 

You need to revisit the study material you used to pass the PSM I & II exams in order to remember what an SM actually does.

Thx for your replies. This were also my thoughts, just wanted it to confirm here with others. Because I also thought "I am not one of the developers, and if I am present on the board, this will also reduce the velocity of the other developers." 

Like you said Daniel, I don't know if this company will accept it like that but I have to think about another way to show them my work, maybe you have suggestions.