Agilent Too Much Calibration - White Paper 5991-1311EN c20140529 [15] free download

File name Too Much Calibration_ - White Paper 5991-1311EN c20140529 [15].pdf

Keysight Technologies Too Much Calibration? White Paper Abstract "Hey Wendle, our cost of sales is increasing, and my boss is riding me hard to reduce it! That calibration budget you submitted is "killing" me. It is just too much calibration. Get back to me tomorrow with a better proposal will you? " "Oh, and by the way could you look at our warranty failures and get that under control? We are up 5% from a week ago." As with another common euphemism, calibration, confidence, and expense all rolls down hill. Introduction High confidence in the test system directly translates to high confidence in the DUT test results and "high" costs buying that confidence. The opposite is true as well. Low confidence in the test system is a guarantee of low confidence in the DUT test results, but a great way to trim costs. Between the "too much" and the "not enough" is the elusive balance point between cost and confidence. This paper will explain the variables that are at work in the world of calibration, how they can be used to find that balance point, and ultimately answer those most important questions. "Will the product work?" and "How much is it going to cost me to know?" It will also provide a common denominator in the languages used by the metrologists and manufacturing. Webster's Dictionary has always been a favorite of mine. He worked night and day to define our language to a "T", no pun intended. Then we create nuances around each word to match our needs in verbal communication. One would think that any words connected with the world of metrology would be meticulously defined and universally used and understood. That however is not the case. Here is some metrological and manufacturing vocabulary as described in Webster's. Author: Todd B. Wendle Keysight Technologies, Inc. Accuracy: "Noun, freedom from mistake or error : correctness 2. conformity to truth or to a standard or model : exactness b : degree of conformity of a measure to a standard or a true value." Calibrate: "Verb, to standardize (as a measuring instrument) by determining the deviation from a standard so as to ascertain the proper correction factors." Now we look at a couple of words from the ma nufacturing test side of the fence. Adequate: "Adjective sufficient for a specific requirement, especially: barely sufficient or satisfactory." Confidence: "The quality or state of being certain: certitude." So, right there in Webster's is the answer to the question "Too much calibra- tion?" The question changes to a statement: "Compare to a known standard a measuring instrument with barely suffi- cient accuracy as to have adequate confidence that the product being tested will perform as specified in the marketplace all at a reasonable cost." Filled with subjectivity, this definition is doomed. The words mean different things to diffe