SudarshanK, RickS

We created two new transfer standard, TSA and TSB in order to facilitate the transfer of laser power calibration between the  national metrology institutes (NMIs) and the various observatories. We are in the process of characterizing these new transfer standard. We have made couple of measurements in the  last few weeks. The result from those measurements will be posted at same later date. Here we present the measurement of temperature coefficient of TSA that was made yesterday.

TSA was in the oven since 3:00 PM  Oct. 12, set at the temperature of 39 deg C. On October 13, the responsivity ratio between TSA and TSB were measured letting the TSA to cool from its heated temperature of 39 deg. C.

The measured temperature coefficient of the newly assembled transfer standard TSA is about 1.5 hops/deg C. When analyzing the data, the points where the temperature gradient is too high, in the beginning, and  where the standard has reached the equilibrium, towards the end, has been ignored. The first fit in the plot is made using all the data under consideration. The second fit is made by decimating the data in order produce equally spaced data and thus remove the bias that arises for having more data at lower temperature difference. The difference in temperature coefficient is minimal from these two different methods.

All the data and the jupyter notebook used to analyze the data can be found here:

/ligo/svncommon/CalSVN/aligocalibration/trunk/Projects/PhotonCalibrator/measurements/LabData/TSA_TSB/t2021-10-13T103030/