There are a number of differences between the older 610M and the current 620M multichannel myographs from DMT;
Control Screen - The 620M has a colour touch screen control panel to navigate through the controls of the unit for carrying out zeroing, calibration, temperature and valve control as well as output range. On the 610M it was necessary to navigate through the menus with function and arrow keys.
Temperature control - On the 610M model there was a fixed temperature output across the heating plate. On the 620M it is possible to control the temperature at each chamber to make sure that they are all at the desired level. More details on this can be found in the 620M user guide.
Transducer connections - The two models have different connector types to interface the chambers to the main unit. On the 620M this is a 9pin d shaped connector whilst on the 610M it was a 5pin circular connector, hence the chambers are NOT interchangeable between the two models.
Voltage output - The voltage output of the 620M is 2.5V full scale whereas it was only 1V FS in the 610M. This is useful when setting the range in LabChart or if you are doing a crude full scale units conversion.