Micro Dynamometers

Knowledge of an air mover’s aerodynamic efficiency and the efficiency of its mechanical drive (motor and bearings) is essential to making further progress in new air-mover designs.

The Micro Dynamometer (μDyno) is designed to measure the power absorption of small fans, blowers and pumps and the power delivery of small motors. It does this by measuring the dynamometer’s stator reaction torque and rotor shaft speed.

The μDyno is compatible with the Model 798 Precision Air Flow Measurement System for simultaneous dynamometer and airflow measurements.

The μDyno is similar in concept to cradle dynamometers used throughout industry for over 75 years. In these designs, a motor/generator is cradled in low friction bearings and the reaction torque to keep the cradle in static equilibrium is measured. Knowing the reaction torque along with rotational speed allows the calculation of shaft power delivered or absorbed by the dynamometer.

The μDyno uses a frictionless, stiction-free flexure pivot to support the armature. This allows for more miniscule torque measurements that could not be made with a typical bearing.

The μDyno is capable of measuring torques of 0.1 to 50 mNm at speeds up to 20,000 RPM. We can measure shaft power ranging from 0.01 to 50 watts with a resolution of about .01 to 5 mW depending on speed. The μDyno is capable of motoring or absorbing operation, making it suitable for testing air moving device elements such as impellers as well as the motors that power the air moving devices.

Currently, the μDyno is only made to order. Please inquire about pricing and lead-times on a model suitable for your applications. Contact us for more details.

μDyno Features

• Entirely frictionless through use of flexure pivot

• Four-quadrant operation allows motor or absorbing operation with clockwise or counterclockwise rotation

• Works with both axial and radial flow fans

• Compatible with the Hill Engineering model 798 Air Flow Measuring System

• Speed range designed for small fans and motors with a range up to 20,000 RPM

• Power measurement range from 0.01 to 50 W

• Can accept holding fixtures for a wide variety of fans, blowers, pumps and motors

• Accurate to 0.01-0.1% for speed measurement, 0.5-2% for torque measurement which leads to ~2% accuracy for power measurements

• Provides digital readout of speed, torque and power measurements