Model ReCT-MMT, Modular, Multi-rotor Tester System
System Hardware
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Model ReCT-MMT (Figure 1) is a modular rotary-engine compression tester system that can be configured to test the compression on up to 4 rotor assemblies simultaneously and to display the results for all rotors on a single display, either as separate traces or superimposed. The Starter Kit (Figure 4) is the basic system configuration that consists of a data Processing Unit (PU) and one data Acquisition Unit (AU). The Kit supports the testing of rotor assemblies, one-assembly-at-a-time. By adding additional data Acquisition Units, the Starter Kit can be expanded and configured to test up to 4 rotor assemblies simultaneously and to display the results in a single display (see sample test records of a 2-rotor test at bottom of this page) for data extraction, analysis and comparison. |
Figure 1. Model ReCT-MMT, Modular, Multi-rotor Compression Tester System.
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The Processing Unit (Figure 2) includes an enclosure containing the analog-to-digital converter, DIN data sockets for up to 4 Acquisition Units plus the power and USB cables, and the system software CD. The Processing Unit receives analog signals from the Acquisition Unit during a compression test and converts them to a digital data stream for transmission to the computer for recording and later display and analysis. |
Figure 2. Model ReCT-MMT, Processing Unit.
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The Acquisition Unit (Figure 3) consists of a precision pressure transducer with attached 30" cable and DIN connector, a spark plug hole adapter with swivel air plug, and a quick coupler fitting for easy connection of the components. An 18 inch extension cable is available at a minimal cost from RDS if additional cable length is required. The Acquisition Unit senses the compression pulse pressure and transmits an analog signal to the Processing Unit for conversion and transmission to the computer. As stated earlier, up to 4 Acquisition Units can be connected to the Processing Units for simultaneous testing of up the 4 rotors. |
Figure 3. Model ReCT-MMT, Acquisition Units.
| The Starter Kit (Figure 4) includes everything, except for a computer, needed to conduct compression tests on single rotors, one-at-a-time while allowing for future system expansion to multi-rotor testing. That is, by connecting additional Acquisition Units to the Processing Unit, the system can be configured to conduct a simultaneous, multi-rotor test of up to 4 rotors. |
Figure 4. ReCT-MMT, Modular, Multi-rotor Tester System, Starter Kit.
System Software
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The ReCT-MMT compression tester system ships with a Lite version of the WinDaq software that supports the acquisition, recording, display and analysis of compression data. Sample rates available with this software are limited to a maximum throughput of 240 samples/second. So, for simultaneous multi-rotor testing, the maximum sample rate is split between the number of channels being recorded. For example, if recording a 3-rotor test simultaneously on three separate channels, the sample rate for each channel would be limited to 80 samples/second (i.e., 240 divided by 3). This rate is adequate for determining consistently- accurate compression measurements in all configurations. However, if the intent is to use this system for detailed analysis of the compression pulses, the upgraded HS version of the WinDaq software is required. Sampling rates up to 14,400 samples/second, total throughput, are supported by the HS version. Compression pulses recorded at such high rates provide very high resolution views of what is happening inside the rotor housing during compression cycles (see high sample rate recording at the bottom of the page). The high sample rate software, WinDaq/HS, is available from RDS at the time of system purchase or at a later date at the same cost. A trial version of the HS software is integrated into the Lite version allowing for up to 40 recordings at high sample rates before the trial license expires. We encourage system users to experiment with the higher sample rates to determine if the higher rates are appropriate for their applications. Details on how to do that are contained in the system user manual. |
Sample Test Records
Figure 5. Two-rotor test results, separate traces in a single display (120 samples/second/channel).
Figure 6. Two-rotor test results, superimposed traces in a single display, blue is rotor 1, red is rotor 2.
Figure 7. High sample rate (2400 samples/second) recording*.
| * High sample rates require upgraded software. See
System Software information above and Purchasing Info. NOTICE: For replacement of a misplaced WinDaq software CD or for the latest version of the software go here.
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