boucle sur graphiques d'une feuille

Sub Echelle(Graph, abscisses, ordonnees)
    With ActiveSheet.ChartObjects(Graph).Chart.Axes(xlValue)
    Min = Application.Min(Range(ordonnees))
    Max = Application.Max(Range(ordonnees))
    
    If Min < 0 Then
    Min = Application.RoundUp(Min, 2)
    Else
    Min = Application.RoundDown(Min, 2)
    End If
    
    Max = Application.RoundUp(Max, 2)
    
    .CrossesAt = Min
    .MinimumScale = Min
    .MaximumScale = Max
    .MajorUnit = (Max - Min) / 4
    End With
    
    With ActiveSheet.ChartObjects(Graph).Chart.Axes(xlCategory)
    Min = Application.Min(Range(abscisses))
    Max = Application.Max(Range(abscisses))
    
    If Min < 0 Then
    Min = Application.RoundUp(Min, 2)
    Else
    Min = Application.RoundDown(Min, 2)
    End If
    
    Max = Application.RoundUp(Max, 2)

    .CrossesAt = Min
    .MinimumScale = Min
    .MaximumScale = Max
    .MajorUnit = (Max - Min) / 4
    End With
End Sub

Sub MiseEchelle()
Dim z As Byte, nbgraph As Byte 'à moins qu'il y en ait plus de 255 !
nbgraph = Sheets(3).ChartObjects.Count
For z = 1 To nbgraph 'pourquoi boucler à l'envers ?!
    Echelle Sheets(3), "Graphique " & z, "abs" & z, "ord" & z
Next z
End Sub

Sub Echelle(ws As Worksheet, Graph$, abscisses$, ordonnees$)
Dim Min#, Max#
With ws.ChartObjects(Graph).Chart

    Min = Application.Min(Range(ordonnees))
    Max = Application.Max(Range(ordonnees))
    If Min < 0 Then
        Min = Application.RoundUp(Min, 2)
    Else
        Min = Application.RoundDown(Min, 2)
    End If
    Max = Application.RoundUp(Max, 2)
    With .Axes(xlValue)
        .CrossesAt = Min
        .MinimumScale = Min
        .MaximumScale = Max
        .MajorUnit = (Max - Min) / 4
    End With
    
    Min = Application.Min(Range(abscisses))
    Max = Application.Max(Range(abscisses))
    If Min < 0 Then
        Min = Application.RoundUp(Min, 2)
    Else
        Min = Application.RoundDown(Min, 2)
    End If
    Max = Application.RoundUp(Max, 2)
    With .Axes(xlCategory)
        .CrossesAt = Min
        .MinimumScale = Min
        .MaximumScale = Max
        .MajorUnit = (Max - Min) / 4
    End With
    
End With
End Sub