Systems and methods for determining fluid rheological characteristics of a fluid used in a subsurface operation are provided. The methods include measuring temperature, pressure, and at least one of a flow rate and a flow velocity of the fluid in a first fluid circuit. A model is based on the temperature, the pressures, and the flow rate or flow velocity. The fluid rheological characteristic of the fluid in a second fluid circuit is determined by measuring a temperature and flow rate and/or flow velocity in the second fluid circuit. The rheological characteristic of the fluid is calculated based on the model employing the temperature and the flow rate/flow velocity of the second fluid circuit.