Viscometer with rotor detection

A viscometer for measuring properties of a sample material, comprising:

• a rotor including a rotor head and a rotor stem;
• a motor and a drive shaft coupled to the motor, the rotor being removably couplable to the drive shaft;
• an upper platen, an upper die, a lower platen and a lower die, the upper and lower dies having an open position to receive a sample therebetween and a closed position to define a sealed test chamber that encloses the rotor head and the sample, the upper and lower dies being separated by a space when in the open position;
• a crosshead coupled to the upper platen, the crosshead adapted to move the upper platen and the upper die relative to the lower platen and lower die;
• a controller;
• a transmitter being positioned to transmit an energy transmission over the lower die and across the space when the upper and lower dies are in the open position;
• and
• a receiver adapted to receive the energy transmission and to output a signal to the controller when the energy transmission is received by the receiver,
• the controller being configured to control closure of the upper and lower dies in response to receipt of the signal from the receiver.