[4] The thermodynamic method was developed concurrently in the 1960s at the University of Glasgow and University of Strathclyde in Scotland, and the National Engineering Laboratory in France (Electricite de France) and Austin Whillier (Chamber of Mines, Johannesburg, South Africa).
Whillier published a paper titled "Pump efficiency determination from temperature measurements" in the October 1967 edition of The South African Mechanical Engineer describing the method.
Using the measurements of temperature, power, and pressure, flow can be back-calculated using the pump equation.
[4] The temperature measurement is critical, and consequently commercial distributors of thermodynamic pump testing equipment often quote an accuracy of greater than 0.001 °C.
[11] Typically, temperature probes are inserted directly into the flow, and pressure measurements are taken from taps on both the suction and discharge sections of the pipe.
[12] The thermodynamic method, however, typically requires only 1-2 diameters of straight pipe upstream of the equipment[10] in order to achieve quoted accuracies.
[13] A number of projects have utilized the thermodynamic method for large scale pump testing and performance review.
The complex algorithms developed as part of the work enabled STW to accurately schedule operation over a set horizon, meeting the demand with very appreciable energy cost reductions - a process simply too difficult for operational staff to do by experience alone.
Two key technologies were amalgamated to provide a network optimisation methodology: thermodynamic pump performance measurement for individual pump and station efficiency analysis, and live hydraulic modelling to assess network routes and their hydraulic profiles.