var
  DEVICE_SCALE_FACTOR: UINT;
...    
  GetScaleFactorForMonitor: function(monitor: HMONITOR;
    var DEVICE_SCALE_FACTOR: UINT): HRESULT; stdcall;
...

  hShcore := GetModuleHandle('Shcore');
  GetScaleFactorForMonitor := GetProcAddress(hShcore, 'GetScaleFactorForMonitor');
  ErrCode := GetScaleFactorForMonitor(Monitor.Handle, DEVICE_SCALE_FACTOR);
  Memo1.Clear;
  Memo1.Lines.Add('DEVICE_SCALE_FACTOR   ' + IntToStr(DEVICE_SCALE_FACTOR));