Unfortunately, there is no physical input on the MPVS Duo for a Rho Cuvette, and this can only be used with the older MPVS Ultra.
Whilst you can measure both admittance and conductance with the MPVS Duo, the measurements are based on different equations, Wei’s equation for admittance and Bahn’s for conductance. Both equations require a Rho value (for blood resistivity) but the Duo generally uses a fixed Rho value which is entered into the unit itself as it has been shown to have little effect on the final Volume calculation for the admittance method.
When applying the volume calibration for large animals in conductance mode, you will need to manually calibrate using Bahn’s equation, which will require the Rho value to be entered into the PV workflow in LabChart's PV Loop Module to get a suitable readout that was previously applied in the MPVS Ultra control software.
For further technical assistance with this or any other issue, please contact ADInstruments Technical Support by clicking HERE