$SqlServerCounterPrefix = 'MSSQL$MSSQL_2008'
$Data = get-counter ($SqlServerCounterPrefix + ":Buffer ManagerBuffer cache hit ratio"),
                    ($SqlServerCounterPrefix + ":Buffer ManagerPage life expectancy"),
                    ($SqlServerCounterPrefix + ":Access MethodsPage splits/sec")
#$Data
$TransformedData = $Data.CounterSamples | Select-Object -Property Path, CookedValue
$TransformedData | Add-Member -NotePropertyName 'Timestamp' -NotePropertyValue $Data.Timestamp
$TransformedData | Format-table -auto

Path                                                                 CookedValue Timestamp
----                                                                 ----------- ---------
\sw-pa-win10mssql$mssql_2008:buffer managerbuffer cache hit ratio         100 2016-10-25 10:18:19
\sw-pa-win10mssql$mssql_2008:buffer managerpage life expectancy           123 2016-10-25 10:18:19
\sw-pa-win10mssql$mssql_2008:access methodspage splits/sec                  0 2016-10-25 10:18:19

Timestamp              buffer cache hit ratio    page life expectancy    page splits/sec
---------              ----------------------    --------------------    ---------------
2016-10-25 10:18:19    100                       123                     0