How to read HardDisk Temperature?

//S.M.A.R.T.  Temperature attritube
const byte TEMPERATURE_ATTRIBUTE = 194;
public List GetDriveTemp()
{
    List retval = new List();
    try
    {
        ManagementObjectSearcher searcher = new ManagementObjectSearcher("root\\WMI", "SELECT * FROM MSStorageDriver_ATAPISmartData");
                //loop through all the hard disks
        foreach (ManagementObject queryObj in searcher.Get())
        {
            byte[] arrVendorSpecific = (byte[])queryObj.GetPropertyValue("VendorSpecific");
            //Find the temperature attribute
                        int tempIndex = Array.IndexOf(arrVendorSpecific, TEMPERATURE_ATTRIBUTE);
            retval.Add(arrVendorSpecific[tempIndex + 5]);
        }
    }
    catch (ManagementException err)
    {
        Console.WriteLine("An error occurred while querying for WMI data: " + err.Message);
    }
    return retval;
}