This adorable little wiry girl is “Sky” – or to be more accurate “GCh AfterAll Painting The Sky.” Americas most prestigious canine club named her the top dog at the 2014 Westminster Kennel Club dog show. Want to know more about Sky’s family tree? Thats easy. We can just hop on the internet and trace her […]
“But It’s NIST traceable” and I’ve Got A Bridge to Sell You in Brooklyn
I am sure that a lot of goofy things can and will be done by folks to call some instrument “calibrated.” Some places simply do a calibration check at one point and presume linearity across a range. Lunacy. What forensic science should have in its analytical instruments is “true scientific instrument calibration” which is part […]
A Forensic Measurement Device is Not an X Box
In forensic science there are many analytical instruments that are used to identify and quantify. For example, there is Gas Chromatography and Breath Testuing Devices (infrared spectroscopy or electrochemical) in DUI. When these devices are deployed in the field or in the laboratory, they are not properly deployed. What we have in forensic science is […]
What does it mean to be NIST traceable?
What does it mean to be NIST traceable? By Janine Arviszu, Certified Quality Auditor [Editor’s note: Too frequently in forensic science, laboratories or laboratory personnel claim that their process or even their whole laboratory is “NIST traceable” as if to act as a shield to ward off external validation. In this article expert witness Janine […]
Happy World Metrology Day!
May 20th every year is a rocking day. Know why? It’s World Metrology Day! Celebrate by checking out of metrology related posts. And celebrate today by only accepting valid measurements. According to www.worldmetrologyday.org Welcome to the 2013 World Metrology Day web site. This year, the theme is “Measurements in daily life” – again we have chosen a […]
Chemical Measurement Process and The Calibration Function: How to best calibrate an instrument used in forensic science
The technical goal of any calibration related effort is t0 achieve a meaningful and valid CMP. According to The International Union of Pure and Applied Chemistry (IUPAC): Chemical Measurement Process (CMP): An analytical method of defined structure that has been brought into a state of statistical control, such that its imprecision and bias are fixed, […]
Improper calibration in true scientific endeavors versus forensic science in the courtroom
In the broader world of science, it is well recognized that parts of the measurement system need to be demonstrated to be in control and properly calibrated as well as properly used by a trained and knowledgable operator. It is through these basic fundamentals that we can infer with sufficient confidence that our testing is […]
How to properly calibrate a machine
In our last post we examined “The importance of calibration in forensic science.” Now I want to drive down deeper into this issue. The calibration of a machine represents the very best results that that machine can ever preform. Over time, through use or non-use, a given machine will not gain tighter precision; it will […]
The importance of calibration in forensic science
The act of calibration is the imperfect scientific action that underlies the validity of the subsequent testing of unknowns. A scientific and properly conducted valid calibration action can possibly yield a valid result. A poor and improperly conducted calibration action will always result in non-validated results and maybe even invalid results. Even within batch calibration […]
Complete Ruling in Commonwealth v Schildt
COMMONWEALTH OF PENNSYLVANIA v. JASON RICHARD SCHILDT IN THE COURT OF COMMON PLEAS DAUPHIN COUNTY, PENNSYLVANIA NO. 2191 CR 2010 OPINION “Facts are stubborn things; and whatever may be our wishes, our inclinations, or the dictates of our passion, they cannot alter the state of facts and evidence.” These famous words were first spoken by […]
Press related to the Linear Dynamic Range Challenge and the Initial Calibration Challenge
Yesterday (January 7, 2012) our office filed a motion that seeks to suppress all BrAC tests in pending cases in the state of Pennsylvania. This would cause all per se DUI cases to be dismissed in Pennsylvania regardless of the BrAC reported results. Here has been the press coverage on the successful Linear Dynamic Range […]
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