I checked the relationship between BNS range and OMC chamber vibration.
The channels are
- K1:PEM-SENSOR_RACK_OMC1_DSUB2_OUT_DQ : an acceleormeter putted on the foot of OMC chamber ("DSUB2" in klog13136)
In the trend plot for this 12hours, we can see the periodical (~140min) pulses in ACC.
At these time (with ~3min deray), the BNS range becames worse about 50kpc (e.g., 300kpc -> 250kpc).
I guess it is comming form the air complessor for a OMC gate valve.
I can analysI it as a PEM injection
start & end GPS time are:
2020-02-25 14:34:05 (1266676296, 1266676344)
2020-02-25 16:56:38 (1266684921, 1266684969)
2020-02-25 19:19:55 (1266693550, 1266963597)
2020-02-25 21:43:55 (1266702185, 1266702232)
2020-02-26 00:07:55 (1266710810, 1266710858)