How to check CPU fan speed? Win32_Fan returns null

I tried to test following technet code, but found the Win32_Fan return null.
Any suggestion?

Thanks!

On Error Resume Next
strComputer = "."
Set objWMIService = GetObject("winmgmts:\\" & strComputer & "\root\cimv2")
Set colItems = objWMIService.ExecQuery("Select * from Win32_Fan")
For Each objItem in colItems
Wscript.Echo "Active Cooling: " & objItem.ActiveCooling
Wscript.Echo "Availability: " & objItem.Availability
Wscript.Echo "Device ID: " & objItem.DeviceID
Wscript.Echo "Name: " & objItem.Name
Wscript.Echo "Status Information: " & objItem.StatusInfo
Wscript.Echo
Next