Main INDEX, Monthly INDEX, PREV, NEXT
Make New Entry, Make Followup Entry

User name Bosted

Log entry time 09:18:04 on January 22, 2008

Entry number 149225

keyword=Target: Target problems

Over the past hour, we have noticed that the PID loop doesn't seems to keep the target temp. at 19K. So I reduced the JT valve, and then it seemed to keep the temp. near 19K, as long as the beam didn't trip off. Then we noticedd that turneing Beam Compensation off, and then the PID loop works fine! This is reproducible. Tried swithcing to the other BCM: problem persisted. Tried rebooting (twice), but haven't got stable beam yet to try if Beam Compensation is working right or not.

However, we now (after both re-boots) are gettings the crazy value of 490 K on the Hesupply termperature. HeHesuply-1R (15 K supply). SO we always have a red alarm on this. But it must be a false reading, or the target wouldn't be cold, I suppose. For now, will leave as is.