powershell only showing last line output

Hi Team,

I'm checking the multiple server performance output. But the export csv output only showing last server performance details. Could you please verify below script  and share the valuable information how to fix this issue.

When using the Append command script not generating any output file

$Servers= import-csv "C:\testcounter.csv"
ForEach($Server in $Servers)
{
$ObjectName=$Server.ObjectName
$CounterName=$Server.CounterName
$InstanceName=$Server.InstanceName
$Server=$Server.Server
$Result=Get-Counter -Counter "\\$server\$ObjectName($InstanceName)\$CounterName"

    $CounterSamples = $Result | % {$_.CounterSamples}

    $MasterArray = @()
 
    ForEach($CounterSample in $CounterSamples)
    {
        $TempArray = @()
        $TempArray = "" | Select Server, ObjectName, CounterName, InstanceName, SampleValue, DateTime

        $Split = $CounterSample.Path.Remove(0,2)
        $Split = $Split.Split("\")

        $TempArray.Server = $Split[0]
        $TempArray.ObjectName = $Split[1].Split("(")[0]
        $TempArray.CounterName = $Split[2]
        $TempArray.InstanceName = $CounterSample.InstanceName
        $TempArray.SampleValue = $CounterSample.CookedValue
        $TempArray.DateTime = $CounterSample.TimeStamp.ToString("yyyy-MM-dd HH:mm:ss")

        $MasterArray+= $TempArray

  }

}
$MasterArray | Export-Csv test.csv