Readings very questionable!

I wanted this device as a second device for measuring at the office. Measurement itself is very simple and comfortable. Unfortunately, the measured values ​​were almost always far in addition to the actual values ​​(comparative measurement with upper arm meter and general practitioner). And far below. So I got myself only became increasingly pleased with the low values, then I very quickly skeptical and have compared. Yes, I also know that you absolutely must pay attention to proper posture and positioning of the device. I have done everything. I now have a Hartmann-unit, which has been recommended by the German Hypertension Society. And here the readings are absolutely comparable to those that measures my upper arm device, and the measurements at the doctor (24hr-long-term measurement). Since a significant difference to remember is already in the inflation since it pumps a lot of solid and the measurement process happens during deflation. When Omron RX Classic 2 is already measured during inflation, that is, you have a lot less time after you press the start button to bring the arm in the correct position, since the measurement process should happen in silence.
When Omron RX Classic 2 you should compare the measurement results with the family doctor and not blindly believe what it indicates definitely times.