Hi Monica Here at Los Alamos National Lab we have used the HP-270 with the Eberline E-600 but not yet with the RadEye GX.
We use the GX with the pancake GM detector. We see a difficulty with the GX when operated in the Scaler “Net” mode in that it shows a “false” indication of low battery. We have verified in the cal shop that the batteries are NOT low. We are continuing to operate the RadEye GM pancake with information to the user about the “false” indication in that mode. We did a study several years back with the E-600 and several different GM pancake detectors to investigate “hot swapping”. We decided that the variations in the GM pancakes were beyond our maximum allowable of +/- 20% response to a designated check source. However you could simply calibrate your GX with many different detectors and instruct the user to select in the GX menu the detector they connect to the GX. We have NOT implemented that option. Draft American National Standard Measurement and Evaluation of Radiation and Radioactive Sources Using Portable Radiation Detection Instruments ANSI N13.65 STRONGLY discourages “hot swapping”. That includes “smart” detectors. However, IF you calibrate the GX to the different detectors then that would not be “hot swapping.” In my 20 some years experience with the Eberline E-600 with “smart” detectors I found one instance of “hot swapping” that caused the detector to misidentify itself. An RCT had connected the E-600 to an NRD then connected to the SHP-400 “smart ion chamber”. The E-600 falsely identified that ion chamber as the NRD. When the detectors were switched back the difficulty went away. We have more than 300 E-600s here at LANL but they are mainly attached to the same “smart” detectors they were initially calibrated with. Since the users tend to keep the same detector connected to their E-600 we have decided to keep our RadEyes connected to the individual detector it was calibrated with. I looked at the LND specs on detector wall thicknesses for their cylindrical GM detectors and I see a potential difficulty there with “hot swapping” UNLESS the GX is calibrated to the specific detector to be used. Take a look at the wall thickness range stated by LND at LNDINC.COM Tom From: Barnby, Monica [mailto:[email protected]] Sent: Thursday, March 03, 2016 7:48 AM To: '[email protected]' Subject: [powernet] RadEye GX with hot dog probe Are you using the RadEye GX with a Thermo HP-270 or Ludlum 44-38 probe? If so, I’d like to talk with you about how they’re deployed. For example, do you allow hot swapping in the field? Any GX with any probe? Monica Barnby Health Physicist PG&E Diablo Canyon 805 545 3566
