Dear Friends,

I am using SKF Microlog for the first time. I am bit uncomfortable with input filter range selection. I my previous analysers(DI 2200 or SPM) i used to find out the haystack position in the high frequency acceleration signature. Accordingly i was selecting the envelope fileter, so that it can cover the haystack completely. But, Microlog is a rout data collection device. i cant aplly the filter individualy at site. The machines were running between 900 to 3000 rpm. Suggest me the best filter range for these machines.

I'm not familiar with the filter ranges on the Microlog that are available but generally you should not include the "haystack: frequencies. Probably a filter in the 5 kHz range for the lower frequencies that you are using and 8 kHz for the higher frequencies. You will see signicantly lower levels that if you included the "haystack" frequenciess but, once you adjust your expectations, you may be able to make sense of the data better.

The Microlog has 4 filter range.
1. 5 to 100Hz
2. 50 to 1000Hz
3. 500 to 10000Hz
4. 5000 to 40KHz

Which one shall i select?

quote:

4. 5000 to 40KHz

Most of the energy in the signal will be in the 5 kHz to 10 kHz range. For an illustration of why this is so, see:

http://vibrotek.com/article.php?article=articles/factors/index.htm