Log entry time 00:10:59 on November 28, 2010

Entry number 341727

Followups:

• 341761 11/28/10 05:57 Carlos BCM u/d readings
• 341895 11/29/10 03:41 jroche Scaler results for the BCM calibration performed on November 24

I performed the analysis of the November 24 BCM calibration and confirmed that the gain of the downstream BCM changed by 10%. The new data also show that the gain of the upstream BCM have not changed which is a pretty good news.

Some details:

• I used data from BCMLOG 167 for the November 24 calibration. BCMLOG 165 is for the November 5 calibration.
• Plot 1 shows the analysis for bcm 1 (upstream) and bcm2 (downstream) versus OLO2, as well as the data for the cross calibration fraday versus OLO2. Plot 2 shows the same thing for the previous calibration November 5.

• at first I was concerned because the calibration constant for the upstream had changed a bit between November 5 and November 24. This is not so when one takes into account the calibration constant between the faraday cup and OLO2 (0.98 for November 5 and 0.969 for November 24). The faraday cup is the only true absolute device.
  Upstream:
  Nov 5: 54.21*0.980=53.1
  Nov 24: 54.8*0.969=53.1
  Downstream:
  Nov 5: 51.62*0.980=50.6
  Nov 24: 47.3*0.969=45.5
  

Figure 1

Figure 2