The VISCOlab PVT is a high-pressure, high-temperature viscometer. It is no secret that we are pretty proud of it. The PVT is a great product. It has the widest temperature range, the widest pressure range, and the widest viscosity range of any viscometer on the market. When you want to achieve accurate viscosity measurement under conditions of extreme pressure and temperature, the VISCOlab PVT is your viscometer.