public class MeasurementWindowViewModel: ViewModelBase
    {
        ServiceDAL _db;
        public ObservableCollection<Measurement> ItemsList
        { get; private set; }
        public RelayCommand _saveCommand;
        public MeasurementWindowViewModel()
        {
            _db = new ServiceDAL();
            ItemsList = new ObservableCollection<Measurement>(_db.GetAllMeasurement());
        }
        public RelayCommand SaveCommand
        {
            get
            {
                return _saveCommand ?? (_saveCommand = new RelayCommand(this.SaveItems));
            }
        }

        private void SaveItems(object obj)
        {
            _db.Save();
        }
    } 

public void Save()
        {
            using (var db = new ServiceContainer())
            {
                db.SaveChanges();
            }
        }

<DataGrid Grid.Row="0" ItemsSource="{Binding ItemsList}" AutoGenerateColumns="False">
            <DataGrid.Columns>
                <DataGridTextColumn Header="№" Binding="{Binding Path = Id, UpdateSourceTrigger=PropertyChanged, Mode=TwoWay}"/>
                <DataGridTextColumn Header="Название" Binding="{Binding Path = Name, UpdateSourceTrigger=PropertyChanged, Mode=TwoWay}"/>
            </DataGrid.Columns>
</DataGrid>

using (PEF context = new PEF())
{
  var contact = context.Contacts.First();
  contact.FirstName = "Julia";
  contact.ModifiedDate = DateTime.Now;
  context.SaveChanges();
}

public IList<Measurement> GetAllMeasurement()
        {
            IList<Measurement> result;
            using (var db = new ServiceContainer())
            {
                result = db.MeasurementSet.ToList(); 
            }
            return result;
        }

class ServiceDAL
    {
        private ServiceContainer db;
        public ServiceDAL()
        {
            db = new ServiceContainer();
        }        
        public IList<Measurement> GetAllMeasurement()
        {
            return db.MeasurementSet.ToList();
        }

        public void Save()
        {
            db.SaveChanges();
        }
    }