No, Delsys sensors are designed to detect minuscule electrical currents appearing on the surface of the skin as a result of muscle contractions. The measurement of skin impedance requires the injection of a known current on the skin, so that the response can be characterized. Delsys electrodes are not designed to inject current in to the skin.
Skin impedance measurements are very difficult to make, and have a very high variability. Once known, this value alone carries little significance. The more informative parameter used to gauge EMG signal quality is the Signal-to-Noise Ratio. Delsys EMG systems have a noise baseline of 5uV (pk-pk). This extremely low noise baseline allows individual motor unit action potentials to be identified from minimal contractions when sensors are properly placed on the skin.