1. What type of QC limits do you use? Statistical limits or tolerance limits or both? both
2. What limiting values do you use, e.g. +/- 3 sigma of check source readings, for count room instruments they must be within 2 sigma. If they are > than 2 but < 3 sigma they can be checked again. Any check > 3 sigma they are automatic rejected. Survey instruments are +/- 20%. 3. What basis do you cite for limits used, e.g. MARLAP, ANSI N42.23, etc.? RG 1.68 4. What is done if source check falls outside limits? > 2 sigma or outside +/- 20% the instrument is rejected, segregated, and sent for repair/calibration. From: [email protected] [mailto:[email protected]] On Behalf Of Thomas J Vandermey Sent: Tuesday, July 19, 2011 12:03 PM To: [email protected] Subject: Powernet: QC charts for RP instruments Request benchmark on RP Instrument QC charts: 1. What type of QC limits do you use? Statistical limits or tolerance limits or both? 2. What limiting values do you use, e.g. +/- 3 sigma of check source readings, +/- 3% or 5% of mean check source reading, variable limits depending on type of instrument, etc.? 3. What basis do you cite for limits used, e.g. MARLAP, ANSI N42.23, etc.? 4. What is done if source check falls outside limits? Thanks very much, Tom VanderMey, CHP Principal Radiological Engineer DTE Energy, Fermi 2 734-586-1539 --- NOTICE --- This message is for the designated recipient only and may contain confidential, privileged or proprietary information. If you have received it in error, please notify the sender immediately and delete the original and any copy or printout. Unintended recipients are prohibited from making any other use of this e-mail. Although we have taken reasonable precautions to ensure no viruses are present in this e-mail, we accept no liability for any loss or damage arising from the use of this e-mail or attachments, or for any delay or errors or omissions in the contents which result from e-mail transmission.
