PRTG Version 17.1.28.1032

I received some bad data from a radio sensor. Normally it receives a signal around -43dBm. However, on a particular day PRTG recorded a signal level of +531dBm. This obviously renders all historical graphs useless.

I tried using the spike filter, and it worked. But ONLY on the insert graphs displayed on the Overview page. If I want to display an individual graph either by selecting the graph on the Overview page or going to the particular interval page then the scale reverts to include the erroneous +531dBm.

The spike filter is not working on the individual graphs, only graphs displayed on the Overview page.

Is there a fix for this?

Article Comments

Hi there,

I assume that the graphs are not recalculated. Sometimes it needs some time till the spike filter is applied to them. But to push this task manually, navigate to "Setup > System Administration > Administrative Tools" and click on the "Go!" button under "Recalculate PRTG Graph Data Cache".

Best regards.


Jan, 2017 - Permalink

Thanks, worked a treat.

The pop-up balloon stated that applying the spike filter might take a few minutes to take affect. I was very patient but it had not taken affect after a few hours. I then restarted the core server and still the spike filter had not taken affect.

Thanks for your quick and accurate response, much appreciated


Jan, 2017 - Permalink