Rick Savage, Dripta

In preparation for shipping the PS11 standard to LLO, which is the working standard for Livingston, we made few responsivity ratio measurements with PS5 (the gold standard).  Attached is a photo of the log sheet (made by Tony) relevant to these measurements. A summary plot of the PS11/PS5 responsivity ratio measurements (the .pdf file) is also attached. The last four data points are the most recent measurements in Back-Front (BF), Front-Back (FB), FB, BF configuration respectively. We don't see any significant impact of the FB-BF configuration change.  The last two measurements uses a 25 ft DB9 cable as will be used by LLO when doing end station measurements with the PS11 standard whereas the two previous measurements used the 10 ft DB9 cable, which is usually used in the Pcal lab for responsivity ratio measurements. Again we don't see any significant impact of using two different cables. During these measurements we turned off the lab lights, something that we did not do during the measurements taken in 2022 or the one in February. 

Note: The plot provides a summary of the PS11/PS5 responsivity ratio trends, which will be converted to responsivity of PS11 as soon as the TSA, TSB and WSS are received from NIST and we make measurements with PS5.