Electrical Check at the Breakout Box

Electrical checks are very important to conduct because if you move forward in the run without conducting them, you might have electrical problems in the experimental set up that you won't know about until you try to take data. At that point you would have to warm up and fix the issue. Thus, there are electrical checks performed at the breakout box, once the tower is installed, at several stages: 300 K, 77 K, and 4.2 K. The procedure to conduct an electrical check is below.

1. First choose which stripline-SQUET card connection you wish to test. Plug in the cable with a D50 connector that leads from the back of the breakout box into the appropriate D50 slot on the ebox for the stripline you've chosen.
2. Get the Digital Multi-Meter (DMM) (which you may have to pull out from the clean room if not in the black tool cabinet) and connect the red and black probes to the DMM. This DMM has the ability to measure in nS, which is why we use it.
3. The checkout will be recorded in an excel document. You can open a previously filled out spreadsheet on the DAQ machine and save a new copy, changing the name to reflect the current day's date. There are three sheets in this document for each dib/ stripline.
4. You need to update the sheet with the side coaxes, SQUET cards, and striplines being used in this run.
5. There are three columns corresponding to 300 K, 77 K, and 4.2 K. You will fill in resistance and conductance values according to what each row requires. Each row dictates where to place the probes on the breakout box. Make sure that for each temperature stage you state who is conducting the electrical check (with initials) and record the date. When values are recorded, they are usually done so to 3 significant figures. If you measure a value that seems too far off from the expected value and you're unsure of why, be sure to discuss this with someone before moving further. Lastly, you will check for any shorts to ground.
6. When you are finished with one dib, move on to the next.
7. When the electrical check at 4 K has been done, place all of the results for the electrical checks on the run diary.