Thread: Multiple varios
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Old December 30th 17, 11:56 PM posted to rec.aviation.soaring
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Default Multiple varios

Maybe not in real life, but in the lab (or the workshop) the response of a Winter vario can be much faster than more modern instruments based on pressure transducers.

The video at https://www.youtube.com/watch?v=XmgH...ature=youtu.be shows the response of a Winter variometer and an LX 5000 connected to the same TE line. The pressure is quickly reduced by about 1 hPa, and the variometers indicate the corresponding lift. The LX 5000 was at the shortest possible time constant and minimum filtering.

The test was initially performed to see if the Winter with a capacity flask would affect the reading of the LX 5000. That was not the case; the LX 5000 had the same response with and without the Winter connected to the TE line.
The Winter vario reacts almost instantaneously to the pressure change, whereas the LX 5000 needs some time to react (basically given by the set time constant). However, the Winter decays exponentially (and slowly) back to zero and the LX 5000 does eventually catch up. This difference in behavior is easily modeled from the different working principles for the two types of instruments, and similar results have also been observed with more recent LX instruments.

In the lab, flow-based varios like the Winter react faster to sudden changes in air movement than pressure transducer varios. Is it the same in real life?

Jan