<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" data-mce-style="font-family: times new roman,new york,times,serif; font-size: 12pt; color: #000000;"><div>Hello Nick,<br></div><br><div>Thank you for sharing this information. The Cryocon was submitted for survey so it could be taken out of Hall B for the debugging but it can be put back into the rack. <br></div><br><div>Regarding the lack of reference ground, I do not have the training to be able to wire the ground to the Cryocon. Would you or anyone else be able to help wire the reference ground?<br></div><div><br data-mce-bogus="1"></div><div>Also, would you have the Quick Start guide that Guy mentioned in his email? I am not able to get to it from Cryocon's website.<br data-mce-bogus="1"></div><br><div>Best regards,<br></div><div>Tyler<br></div><br><hr id="zwchr"><div><b>From: </b>"Nicholas Sandoval" <sandoval@jlab.org><br><b>To: </b>"Tyler Lemon" <tlemon@jlab.org><br><b>Cc: </b>"Renuka Rajput-Ghoshal" <renuka@jlab.org>, "Scot Spiegel" <spiegel@jlab.org>, "Christiana Wilson" <grenoble@jlab.org><br><b>Sent: </b>Wednesday, November 23, 2016 8:32:26 AM<br><b>Subject: </b>More information for cernox dropout on cryocon<br></div><br><div>Hi Tyler,<br><br>I compiled a bit more information for you to help with your investigation: <br><br>1)Attached plot of four cernox sensors showing the dropout<br> - This behavior started during the transition from ~80K to ~4K<br> - The logger(MYA archive) reports 0 the same time the local display reads ...clipping..<br><br>2)Cernox Cabling diagram and Calibration curves for the sensors in question is B00000-09-0178 Rev A<br> -From this drawing you can obtain the serial numbers <br> Directory:<br> M:\hallb_eng\CLAS12\Magnets\Torus\JLab Torus\C&I_Torus\Controls_&_Wiring\Drawings and Diagrams\In Work Drawings\Torus PDF Files 08-18-2016<br> -Using the serial numbers you can look up the calibration curve for a starting point on the dummy loads <br> Directory:<br> M:\hallb_eng\CLAS12\Magnets\Torus\JLab Torus\C&I_Torus\Controls_&_Wiring\Calibration Information\Cernox Background Info<br><br><br>3) Looking at Guy's response to Robert and also from his correspondence with me I would start with the lack of reference ground. This probably means any dummy load testing may be better simulated as installed in the Hall. Try to make the controller display clipping first then add a reference ground and see if it goes away, etc. <br><br>CryoconTech Support (Guy):<br> "You are correct that the message ..Clip. should not be on steadily. The<br>message will sometimes flash with ACR sensors when the unit is first<br>searching for the resistance. If it stays on, there is a problem,<br>usually from shielding or grounding. The message indicates that there is<br>an over-voltage condition on the input. It has nothing to do with the<br>calibration curves you uploaded."<br><br><br>"Please be sure that there is a connection between the rear panel of the<br>instrument and a ground point. This can be done by connection of the<br>input cable shield to a ground. Since the two-wire external power supply<br>does not provide a ground reference, an external one needs to be made.<br>Otherwise, AC pickup can cause erratic readings."<br><br>Best Regards,<br>Nick</div></div><br></div></div></body></html>