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The principles of measurement should have been much more frequently involved than only when we need to customize an instrument. At present, the measuring techniques have completely digitized. The principles we learnt in undergraduate physics experiment class may not applicable now. Before the electronic age, most measuring instruments convert the physical quantity into a pointer-scale indicator where human eyes are required to determine the quantity. For example the thermometer converts the temperature into the height of the liquid in a tube. Even the reflective index, if measured by an classic Abbe reflectometer, was converted into the sharpness of the edge between two blocks of color, also requiring human eyes. Students are trained to read as accurately as possible by eyes in the labs during undergraduate study, but after they enter their PhD projects they practically encounter only modern instruments which display digits on a screen or export ascii text files in a computer. Therefore they easily lost the caution of measurement non-ideality, or they lack the knowledge to care about this†.
The modern measuring system starts almost inevitably from sensors, a large class of electronic components, rather than the human eyes. Digits on the screen can of course be consistently read by all people including the physically challenged provided additional techniques. This is the triumph of the electronic age indeed. But the problems do not disappear; they are instead hidden inside the instrument between lines of the electronic circuits. What was once understood in an undergraduate class becomes too technical to explain now. Therefore although we have long entered the electronic age we still skip this part in the undergraduate education. And most graduate students trust the instrument companies very much in their PhD project until the problem becomes explicit. Problems become explicit when we need to design a measurement system customized for a research purpose.
In China there is such a class called like “Principles of Electronic Measurement”. But it is limited in the departments of electronics, electrics, industrial control, automation, etc., out of the sight of the students of physical sciences. But my feeling becomes stronger and stronger that experimental physical research must based on full knowledge about the general measurement principles as well as emerging measuring techniques. Otherwise, the perspectives of scientific research is limited by instrument company instead of pioneered by scientists. I am interested in how widely students in other countries can access this course.
That’s why I, different from the reviewers on its item page on Amazon.com, think this book useful. Indeed as one of the reviewer commented:
If you hope to use this book to get a general overview of measurement systems, then you may be alright, but if you want to be able to perform actual calculations, you should look elsewhere.
This may be insufficient for a text book for professional fields e.g. applied electronics or industrial control, but the practical case for physical sciences is that students need informed in the first place what they need to care about, in a systematic way rather than tips and tricks. I also compared this book with several Chinese textbooks of electronic measurement, and I found the selection of content is the best in Bentley’s book for informing electronic non-experts the necessity to care about what. It becomes rather easy task for one to find more literature for special cases after informed, whereas being completely uninformed or knowing only random, incomplete tips will mislead a researcher quite far.
† I am, of course, talking about the situation in China only.
