Here is a small bit of PowerShell that monitors the memory usage of a process and outputs the results in a CSV format in the locale of your choosing. I needed this because the sysadmins disabled perfmon and I really wanted to import the raw data into Excel to produce some graphs.

You can use it as follows

PS> Set-ExecutionPolicy -Scope Process -ExecutionPolicy Bypass
PS> Monitor-Process -Interval 30 -Locale 'nl-NL' -ProcessName winword | Tee-Object -Append -FilePath C:\Temp\test.txt
-OR-
PS> Monitor-Process -Interval 30 -Locale 'nl-NL' -ProcessId 5800 | Tee-Object -Append -FilePath C:\Temp\test.txt

function Format-MemoryAsCSV
{
  [CmdletBinding(SupportsShouldProcess=$false)]   
  param  
  (   
    [Parameter(Mandatory=$true, ValueFromPipeline=$true, ValueFromPipelineByPropertyName=$true, HelpMessage="Proces to get/format memory from")]    
    [Alias("Process")]    [ValidateNotNull()]    
    $InputObject,
    
    [Parameter(Mandatory=$false, HelpMessage="Which locale to use when formatting numbers (en-US, nl-NL")]
    $Locale = [System.Threading.Thread]::CurrentThread.CurrentCulture.Name 
  )
   process 
   {
            $localeObject = new-object CultureInfo($Locale)
            $Separator = $localeObject.TextInfo.ListSeparator
            $item = Get-Item $InputObject -ErrorAction SilentlyContinue
            $PrivateMemorySize64 = [math]::round($_.PrivateMemorySize64/ 1MB,1).ToString($localeObject ) #Total amount of memory allocated to proces. I.e.. RAM + pagefile. Excludes sharedlibs
            $VirtualMemorySize64 = [math]::round($_.VirtualMemorySize64/ 1MB,1).ToString($localeObject ) #total virtual address space of the process
            $WorkingSet64        = [math]::round($_.WorkingSet64/ 1MB,1).ToString($localeObject ) #Amount of memory thats held in physical RAM chips
            Write-Output "$([DateTime]::Now.ToString($localeObject))$($Separator)$($_.Id)$($Separator)$($_.Name)$($Separator)$($PrivateMemorySize64)$($Separator)$($VirtualMemorySize64)$($Separator)$($WorkingSet64)" 
     }
}

function Monitor-Process
{
    [CmdletBinding(SupportsShouldProcess=$false)]
    param  
    ( 
    [Parameter(Mandatory=$false, HelpMessage="NUmber of seconds between samples")]     
    $Interval  = 30,

    [Parameter(Mandatory=$false, HelpMessage="Which locale to use when formatting numbers (en-US, nl-NL")]
    $Locale = [System.Threading.Thread]::CurrentThread.CurrentCulture.Name, 
  

    [Parameter(parametersetname="ByName")]
    [Parameter( Mandatory=$false, HelpMessage="Name of the process(es) to monitor")]
    $ProcessName,

    [Parameter(parametersetname="ByPID")]
    [Parameter(Mandatory=$false, HelpMessage="PID of the process to monitor")]
    $ProcessId
    
    )

    process
    {
        do
        {
            switch ($PsCmdlet.ParameterSetName)
            {
                "ByName" {  Get-Process -Name $ProcessName -ErrorAction SilentlyContinue  | Format-MemoryAsCSV -Locale $Locale }
                "ByPID"  {  Get-Process -Id   $ProcessId   -ErrorAction SilentlyContinue  | Format-MemoryAsCSV -Locale $Locale }
            }

            [System.Threading.Thread]::Sleep(1000 * $Interval)
        } while ($true)
    }
}