Spindle IKA VOL-C-RTD-2.1 The optional chamber VOL-C-RTD-2.1 for VOLS-1 is especially suitable for expensive and valuable samples. A temperature sensor is already integrated in the chamber and thus allows for temperature measurement during viscosity determination. It is required to use the VOL-SP-2.1 spindle in combination with the 2.1 ml chamber VOL-C-RTD-2.1. The spindle is available as accessory.