<html><body><div style="font-family: times new roman,new york,times,serif; font-size: 12pt; color: #000000"><div data-marker="__QUOTED_TEXT__"><div style="font-family: times new roman,new york,times,serif; font-size: 12pt; color: #000000"><div><div style="font-family: times new roman,new york,times,serif; font-size: 12pt; color: #000000"><div>Hello Marco,<br></div><br><div>My answers to your questions are below:<br></div><br><div><span style="color: rgb(0, 0, 255);">1.) Did you ever turn off the lamp after each measurements? </span></div><div><span style="color: rgb(0, 0, 0);">No, we did not turn off the lamp between measurements. We left it on all day because we did not turn the lamp off between measurements of the mirror.<br></span></div><div><span style="color: rgb(0, 0, 255);"><br></span></div><div><span style="color: rgb(0, 0, 255);">2.) Did you take note of the voltage supplied to the lamp?</span><br></div><div><span style="color: rgb(0, 0, 0);">The lamp has 10.65 V and 3.84 A. This was not changed throughout the day and is matches what settings we recorded on 6/29/2017. <br></span></div><div><span style="color: rgb(0, 0, 255);"><br></span></div><div><span style="color: rgb(0, 0, 255);">3.) Did you ever turn off the picoamperometer? </span></div><div><span style="color: rgb(0, 0, 0);">No. As with the lamp, we left it on because we did not turn the picoamperometer off either between measurements of the mirror.<br></span></div><div><span style="color: rgb(0, 0, 255);"><br></span></div><div><span style="color: rgb(0, 0, 255);">4.) Did you redo the zeroing before the measurements?</span></div><div><span style="color: rgb(0, 0, 0);">Yes. The LabVIEW program Peter Bonneau wrote for the test station's data acquisition zeros the meter at the start of every set of measurements.<br></span></div><div><span style="color: rgb(0, 0, 0);"><br></span></div><div><span style="color: rgb(0, 0, 0);">We will start with step 2 of the plan today.<br></span></div><div><span style="color: rgb(0, 0, 0);"><br></span></div><div><span style="color: rgb(0, 0, 0);">Best regards,<br></span></div><div><span style="color: rgb(0, 0, 0);">Tyler<br></span></div><div><span style="color: rgb(0, 0, 0);"><br></span></div><br><hr id="zwchr"><div><b>From: </b>"Mirazita Marco" <Marco.Mirazita@lnf.infn.it><br><b>To: </b>"Mindy Leffel" <leffel@jlab.org><br><b>Cc: </b>"dsg-rich" <dsg-rich@jlab.org><br><b>Sent: </b>Wednesday, July 19, 2017 8:04:57 AM<br><b>Subject: </b>Re: [Dsg-rich] RICH - reflectivity test station calibration stability results<br></div><br><div>Hi all,<br>I did some plots of the data you took, it seems in fact that the system <br>is very stable if nobody touches anything. From the plots, we can assume <br>about +/-1% systematic uncertainty.<br>There are a couple of things I forgot to mention in the measurement <br>plan:<br>- Did you ever turn off the lamp after each measurements? Did you take <br>note of the voltage supplied to the lamp?<br>- Did you ever turn off the picoamperometer? Did you redo the zeroing <br>before the measurements?<br>I think we can now move to step 2 of the plan, that I copied below.<br>Thank you to everybody,<br>Marco<br><br>2) Verification of the stability of the reflectivity measurements using <br>the control mirror<br>Repeat the cycle of calibration and reflectivity mesurerement few times <br>during one day:<br>- align the system for the calibration run<br>- take calibration data<br>- install the control mirror and align the system for reflectivity run<br>- take a reflectivity run<br>Once the mirror has been installed the first time, it should not be <br>touched anymore for the next measurements, the alignment procedures <br>should involve only the photodiode B. Again, please take note of the <br>times.<br>==>> For each measurement, take also note of the lamp voltage supply. <br><<==<br><br><br>Il 2017-07-19 13:00 Mindy Leffel ha scritto:<br>> I see highlighting:<br>> <br>> On 7/18/2017 6:28 PM, Amrit Yegneswaran wrote:<br>> <br>>> good work tyler.<br>>> <br>>> w.r.t. line #8: (see below, i reformatted your e-mail), i don't see<br>>> any highlighting in the excel sheet.<br>>> don't understand where you come up with the <1% error you quote?<br>>> <br>>> fix your significant figures, do let excel decide!<br>>> <br>>> w.r.t. line #13: perhaps initially the calibration may be dependent<br>>> (you didn't take a measurement as soon as you turned it on, did<br>>> you?), but once the lamp has warmed up, the calibration doesn't<br>>> change.<br>>> <br>>> finally, calculate the confidence level of your measurement.<br>>> <br>>> amrit<br>>> <br>>> am<br>>> <br>>> w.r.t. #13<br>>> <br>>> -------------------------<br>>> <br>>> FROM: "Tyler Lemon" <tlemon@jlab.org><br>>> TO: "dsg-rich" <dsg-rich@jlab.org><br>>> SENT: Tuesday, July 18, 2017 4:43:39 PM<br>>> SUBJECT: [Dsg-rich] RICH - reflectivity test station calibration<br>>> stability results<br>>> <br>>> Hello Marco Mirazita,<br>>> <br>>> * Attached in "_2017-07-18_calibration_stability_tests.xlsx_" are<br>>> the results from today's calibration stability of the reflectivity<br>>> test station.<br>>> * In the Excel sheet, there is a table of all the raw data for the<br>>> calibration runs.<br>>> <br>>> * At the end of the data, there are statistics for the data.<br>>> * For the stability test, we turned on the lamp source at 8:00AM<br>>> to allow it to heat up.<br>>> * We aligned the test station's optics for a calibration run and<br>>> took data on every hour starting at 10:00AM until 4:00PM (total of<br>>> seven calibration runs).<br>>> <br>>> * After the initial alignment, the dark box was not opened and the<br>>> position of the photodiodes was not changed.<br>>> * The results support that the calibration measurements do not<br>>> vary over the course of a few hours if the test set-up is not<br>>> modified in any way.<br>>> * The calibrations for each wavelength has a calculated error of<br>>> less than 1%, with the exception of the 300nm wavelenth (highlighted<br>>> in yellow).<br>>> <br>>> * The 300nm-wavelength calibration results from 10:00AM are also<br>>> highlighted in yellow. This measurement seems to be the source of<br>>> the larger error for the 300nm wavelength calibration.<br>>> * Also attached in "_all_calibrations.xlsx_" is data for all<br>>> calibrations we used for all reflectivity tests, including the ones<br>>> from today.<br>>> * The data is arranged in the same way as the stability test<br>>> results with statistics at the end.<br>>> <br>>> * Using all calibration run data, the calculated error of the<br>>> calibration is much higher (~10% to ~17%). This most likely is due<br>>> to the realignment that takes place between calibrations and between<br>>> the testing of mirrors.<br>>> * In conclusion, the calibration does not seem to depend on the<br>>> amount of time the lamp source is on.<br>>> <br>>> * Using the data from all calibrations, the main source of error<br>>> appears to be the realignment of test station optics.<br>>> <br>>> Best regards,<br>>> <br>>> Tyler<br>>> <br>>> _______________________________________________<br>>> Dsg-rich mailing list<br>>> Dsg-rich@jlab.org<br>>> https://mailman.jlab.org/mailman/listinfo/dsg-rich [1]<br>>> <br>>> _______________________________________________<br>>> Dsg-rich mailing list<br>>> Dsg-rich@jlab.org<br>>> https://mailman.jlab.org/mailman/listinfo/dsg-rich [1]<br>> <br>> <br>> <br>> Links:<br>> ------<br>> [1] https://mailman.jlab.org/mailman/listinfo/dsg-rich<br>> <br>> _______________________________________________<br>> Dsg-rich mailing list<br>> Dsg-rich@jlab.org<br>> https://mailman.jlab.org/mailman/listinfo/dsg-rich<br>_______________________________________________<br>Dsg-rich mailing list<br>Dsg-rich@jlab.org<br>https://mailman.jlab.org/mailman/listinfo/dsg-rich</div></div></div></div><br></div></div></body></html>