Data Conversion Section Links

  1. Home Page
  2. Introduction
  3. Goals
  4. Why Digitize?
  5. Number Representation
  6. Digital to Analog
  7. Analog to Digital
  8. Applications
  9. Literature Citations


We live in a digital age. Electronic instrumentation is employed for almost all quantitative analytical measurements. Even balances are now electronic. Reports are produced on computers. Data are summarized in spreadsheets and digital notebooks. Plots are hardly ever made by hand. Thus, we need to get data, ALL data, from the outside world into the computer somehow. One could, of course, make manual measurements (reading a buret, using standard weights on a two-pan balance), convert those readings to numbers, and then type the results into the computer. In fact, it is much easier, more reliable, and usually less expensive, to directly digitize data before it is ever seen by humans. In modern instruments, digitization is ubiquitous. So why even talk about it?

First, every measurement that involves digitization imposes an information transformation process between the chemical entity we are using and our knowledge of what is happening. It's the difference between experiencing blowing and drifting with our senses and seeing a blizzard through a window. Yes, the information about winter weather is present when we are looking through the glass, but "winter" has been transformed from something experiential to something representational. Similarly, digitization interposes a lossy conversion process between what is happening in the real world and what we see of what is happening.

Second, when we seek to interpret our data, knowing how digitization works can inform what algorithms we choose, what instruments we choose, and what measurement parameters we set.

Third, when we see data collected by others, we can critically evaluate what measurement artifacts may be in their data that they have missed (if they don't know what you're about to learn!). and

Finally, if we ever seek to devise a new measurement strategy or design a new instrument, we'll know what engineering choices we and our collaborators have.