D.Marchiori (DMA) manufacture double or triple tachometer testers. They use precision controlled DC motors with coaxial optical encoders controlled by a dedicated microprocessor. A quartz timing circuit provides maximum accuracy and control stability. Speed values (% or RPM), rotation direction, transmission ratio and 100% RPM values can be selected separately for each motor. The test set can apply star or delta resistive load and read the output voltage for generator checks; by entering RPM and test voltage limit values the full generator check can be automatically carried out. The internal printer provides copy of the test results. Safety limits to protect UUT can be set separately for each motor.
The tachometer testers are part of DMA aircraft ground support equipment (AGSE) range.