wordpress remove backend admin bar

wpse_76491_admin_bar_menu.php

// remove admin bar at backend
//plugin: http://wordpress.org/extend/plugins/wp-admin-bar-removal/
add_action( 'admin_bar_menu', 'wpse_76491_admin_bar_menu', 200 );

function wpse_76491_admin_bar_menu()
{
    global $wp_admin_bar;
    if ( !is_object( $wp_admin_bar ) )
        return;

    // Clean the AdminBar
    $nodes = $wp_admin_bar->get_nodes();
    foreach( $nodes as $node )
    {
        // 'top-secondary' is used for the User Actions right side menu
        if( !$node->parent || 'top-secondary' == $node->parent )
        {
            $wp_admin_bar->remove_menu( $node->id );
        }
    }
    // end Clean
}