Adding extra series to scattergraph - excel

Question

I am trying to create a code which adds series to a scatter-graph. The code runs but there is about 100 extra series of data added which were not specified. My vba skills are basic.
Dim DownSweep As Chart
Dim xrng As Range
Dim yrng As Range
Dim title As Range
Dim dsvt As Worksheet
Dim dst As Worksheet
Dim i As Integer
t = 1
CLEAN:
If t < ActiveWorkbook.Charts.Count + 1 Then
If ActiveWorkbook.Charts(t).Name = "DownSweep Graph" Then
Application.DisplayAlerts = False
ActiveWorkbook.Charts("DownSweep Graph").Delete
Application.DisplayAlerts = True
t = t + 1
GoTo CLEAN
End If
End If
Set dst = Worksheets("Template 2 - Down Sweep")
Set dsvt = Worksheets("DownSweep ViscosityTemperature")
Set xrng = dsvt.Range(dsvt.Range("C2"), dsvt.Range("C2").End(xlDown))
Set yrng = dsvt.Range(dsvt.Range("F2"), dsvt.Range("F2").End(xlDown))
Set title = dsvt.Range("F1")
dsvt.Range("E1").Select
Set DownSweep = Charts.Add
DownSweep.Name = "DownSweep Graph"
With DownSweep
.ChartType = xlXYScatter
.SeriesCollection.NewSeries
.SeriesCollection(1).XValues = xrng
.SeriesCollection(1).Values = yrng
.SeriesCollection(1).Name = title
End With
title = title.Offset(0, 1)
For i = 2 To 99
With DownSweep.SeriesCollection.NewSeries()
.XValues = xrng.Offset(0, i - 1).Value
.Values = yrng.Value
.Name = title
End With
title = title.Offset(0, i)
Next i
End Sub
How do I prevent this from happening?
Any help would be appreciated.

Answer 1

That's because you're selecting a cell within the source data prior to adding the chart. So it automatically sets that data as it's source and creates the series collection.
Therefore, either make sure that the active cell does not reside within the source data or use the following code to delete the existing series collection prior to adding your new series collection.
With DownSweep
Do While .SeriesCollection.Count > 0
.SeriesCollection(1).Delete
Loop
End With