Thermodynamic method for measuring turbine/pump efficiency - Department of Hydro and Renewable Energy,Indian Institute of Technology Roorkee
Thermodynamic method for measuring turbine/pump efficiency


Thermodynamic Method for Measuring Turbine/Pump Efficiency


Thermodynamic Method Facility Brochure       thermodynmics_brochure_cover.jpg (862 KB)


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      The Instrumentation laboratory HRED, IIT Roorkee has recently developed capability to carry out Field efficiency by Thermodynamic testing method as per IEC 60041:1991: in addition to its vast experience of carrying out efficiency testing of over 250 hydropower plants of various capacity in different terrain and states by various other methods of Discharge method for Field efficiency test having Hydro Turbine/Pump Efficiency Testing facility and discharge measurement facility since 2004, Instrumentation lab, has been providing technical consultancy and efficiency testing of pump/turbine for our clients across the globe.

Advantages of Thermodynamics Testing

  • Determination of the absolute hydraulic efficiency with lower uncertainty as compared to other methods.
  • Direct measurement of turbine / pump efficiency without any need of generator / motor efficiency.
  • Universal applicability to turbines, pump turbines and pumps.
  • Providing affordable facility to small hydro manufactures for design verification.
  • No discharge measurements required.
  • No major shutdown is required in thermodynamic method of efficiency measurement as compared to other methods.
  • No straight length requirement of water conductor system.

Principle of Thermodynamics Method

The thermodynamic method results from the application of the principle of conservation of energy (first law of thermodynamics) to a transfer of energy between water and the runner/impeller through which it is flowing. The specific mechanical energy at the runner/impeller may be determined by measurement of the performance variables (pressure, temperature, velocity and level) and from the thermodynamic properties of water. To establish the efficiency, the need to measure the discharge is eliminated by using the specific mechanical energy together with the specific hydraulic energy

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General schematic of measuring instruments (source: IEC 60041:1991-11)


Salient Features

  • Thermodynamic testing method as per IEC 60041:1991
  • Applied for accreditation as per ISO/IEC 17025:2017 by National Accreditation Board for Testing and Calibration laboratories (NABL)
  • Testing carried out by Instrumentation lab HRED IITR is as Independent/ third party institution
  • The range could be extended to cover lower head subject to analysis of the accuracy of the measurement
  • High accuracy Temperature measuring instruments of 0.001oC
  • Tapping at high pressure side measuring section is set near to inlet of machine
  • Low pressure measuring section is free surface at low pressure side of a turbine or in Draft tube
  • Pressure transmitter is used for measuring pressures at high pressure section and low pressure section.
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SBE 38 Digital Thermometer
(Accuracy 0.001oC, Least count 0.0001oC)


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Absolute Pressure Transmitter - different pressure range as per site requirement

Digital Power Analyzer
(Accuracy 0.1%, Least count 0.0001 kW)

      Measurements by the thermodynamic method are not recommended where unfavorable condition exists such as irregular temperature or velocity distribution in the measuring section, low head plants and unstable temperature.



Instrumentation Laboratory,
Department of Hydro and Renewable Energy,
Indian Institute of Technology
Roorkee, Roorkee-247667
Uttarakhand, India
Phone : Off.(+91 1332) 285821, 285841
E-mail :,,,,
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