Reason for failed floating calibration:

1). Check the signal transmission wires if connect well. Refer to above red square parts.

2). Earth wire must connec to ground directly to avoid static interference. This is very important.

3). Make sure there is no foreign material under the laser nozzle. 

4). Mae sure there is no coating on metal sheet, otherwise laser nozzle can not detect the signal.

5). Make sure there is no electromagnetic interference nearby. Such as transformer substation.

6). The data displays signal on console must be very stable, at most the last 1 or 2 digits can be

changeble. Regular data is about 70000.