Sensitivity Training – Detection Limits Versus Control Limits
My latest What's New blog post doesn't discuss that sensitivity (i.e., being empathetic to others' feelings). What is explains is how a test method's limit of detection (LOD) and control limit are related. A method's LOD is the lowest level of anylate it can reliably detect. In contrast, control limits are determined based on the operational demands of the system. Control limits must be set at levels greater than test methods' LOD, and preferably greater than methods' limits of quantification (LOQ). When new test methods with greater sensitivity are developed, there is no need to change control limits unless the historical limits were insufficient. I wrote my Sensitivity Training post in response to questions I've received about whether control limits should be changed when more sensitive test methods become available. Read the full post at Sensitivity Training - Detection Limits Versus Control Limits and let me know your thoughts and questions.
Director of Industry Affairs at PMPA: Precision Machined Products Association
4 年"When new test methods with greater sensitivity are developed, there is no need to change control limits unless the historical limits were insufficient.?" Over my career , I have watched technology evolve, and I call this "The Case of the Receding Zero" now that we can count atoms, there is no such thing as zero. Parts per Billion are now routine, they used to be Zero. Or am I being overly sensitive?
Independent Research Professional
4 年Matrix effects also have to be considered. For example, the LOD for cyanide in water is 20 ppb, but in a metalworking fluid matrix, it is about 80 ppb. EPA knew the difference, but state inspectors did not. Many interesting conversations followed.
Freelance Research Chemist
4 年Thanks, Fred. This principal is so fundamental, yet so often mispresented. It applies to many areas, not just in the microbiological areas. A good example is drinking water analysis. Analysis methods are now often extremely sensitive, thus allowing uniformed to misrepresent and misinterpret reported results...
Account Manager
4 年Good Visual!