Odd ispindel activity - jumping SG trace

[Neale]

I am currently brewing a fairly simple pale ale based on Langham Hip Hop. Its a split batch with the only difference being the whirlpool additions.

The SG trace on one of the batches appears to be jumping by a couple of points every now and then. Its obviously not that the actual SG is changing so whats going on? It also seems that the time between jumps is extending as time goes on. The other ispindel's SG trace is pretty smooth as you would expect.

I have a transparent FV so I can see the ispindel and its not caught on anything and is pretty clean. I've used it before and it didnt do this. I dont expect perfect SG readings but this is a bit weird. Anyone got any ideas?

 

[Agentgonzo]

It's probably a yeast that builds up on the ispindel gradually, then the jump will be even a blob of it falls off

 

[RoomWithABrew]

Interesting the latency of the bump interval looks like it has increased by about 50% each time. Guesstimate made without measuring using ruler etc.
But krausen or settling yeast on the side of the ispindel is my guess.

 

[Neale]

I dont think it is krausen related its pretty clean and has been for days.

Heres a close up of the section with the jumps in it. Its not quite 50% extra time each time but its not too far off. I'm thinking it must be something electrical or software based to be so similar on each of the jumps.

 

[Nucbrewer]

All my iSpindels have done this.

 

[RoomWithABrew]

Mine shows variations with temp as the wine is only loosely controlled to stop it getting to cold. But not with an increasing interval. There's no krausen effect with wine it's quite a dull ferment to watch.