Dan B., Cao, TJ

We swapped the TCSY flow meter because it was showing signs that it was going bad again (see alog51823). To do this, we followed the procedure that Betsy outlines in alog32776. We only encountered a few minor issues:

1. When turning off the power supplies and RF, we also turned off the supply label "Phoenix". This powers the TCS access system, so when we brought this down, we also brought every laser down. Boo.
2. The plastic nut that screws the flow meter on the pipe T, was impossible to remove by hand. We used a small pipe wrench to get it going for the removal. On the new one I had to use the pipe wrench as well, because it was very difficult to move by hand from the start. I didn't go as far down the threads as the previous flow meter because I didn't want to over tighten and there was plenty of paddle down into the main stream.
3. The settings listed in Marc's comment to Betsy's alog didn't match the ones on the TCSX flow meter, specifically, the K-factor and the averaging. We first tried the k-factor alog setting, 135, which gave us a flow of ~9gpm. The chiller is only pushing at 4gpm, so this is obviously wrong. We then tried the setting that the TCSX flow meter is running, 385, and that gave us the usual 3.3gpm. This matches what the analog meter on the pipe just before the flow meter reads. (A quick note: to adjust the magnitude of this number, get the decimal point to flash  and then push the white button to move it.) The averaging has since been updated since Betsy's alog, so I set it to 10seconds.

The flow meter that was taken out did not seem as dirty as the pictures of previously removed flow meters (see attachment). Hopefully this helps with some of the flow issues we have seen lately.

Summary of settings:

FLO Unit (Flow Unit) = G/m (default was L/m)

FActor (K-Factor) = 365.00 (default was 60)

AVErage (Average) = 10

SEnSit (Sensitivity) = 0

4 Set (4mA Set Point) = 0 G/m

20 Set (20mA Set Point = 10 G/m (default was 160)

ContrAST (Contrast) = 3

Serial numbers:

Old - 61308140034

New - 61606071363