Bits, digital

On one hand, the fastest 16 bit digitizer runs at 1.5 Mhz it is therefore theoretically (Shannon) impossible to make digital EC measurement at frequencies over 750 kHz. 

A 10-bit digital system uses the sequence 180, 90, 45, 22.5, etc., to transmit the azimuth value. What is the accuracy of the transmission Give the binary numbers for S-23-E by excess, default and nearest. 

Commercial LIMS appeared on the market in the early 1980s. These operated on then state-of-the-art minicomputers such as the 16-bit Hewlett-Packard 1000 and 32-bit Digital VAX system. By the late 1980s, several DOS-based PC LIMS operating on the primitive PC network were available. By the early 1990s, most LIMS started using commercial relational database technology and client/server systems, which operated on UNIX or the new Windows NT platform. The most advanced LIMS utilize server-based architecture to ensure system security and control. 

Figure 1.32 Increase in sensitivity via increase in ADC resolution, (a) A tiny signal of impurity at 8 3.90 appears clearly with a 16-bit digitizer, (b) The signal at 8 3.90 is smaller when a 12-bit digitizer is used, (c) The signal at 8 3.90 is hard to see when the spectrum is recorded with an 8-bit digitizer.

Routinely-used circuits can reach 125000 Hz for 16-bit digital analogue converters beyond this, the dynamic range must be sacrificed. 

The SAR studies reported here were done using the ADAPT computer software system (35,36). ADAPT has been implemented on the Department of Chemistry MODCOMP 11/25 16-bit digital computer in FORTRAN. The fundamental steps involved in performing an SAR study using this system are shown in Figure 1. The individual steps are implemented in a series of independent programs that can be executed individually. They perform the mutually supportive tasks necessary for an SAR study as follows ... 

Fig. 3. Spectrum from bandpass delta-sigma modulator (1-bit digitizer) wiUi clock signal at 800 MHz and input signal at 1020 MHz.

The following photographs in this book were produced using a 12 bit Digital camera-system from CAMAG 8, 9a and 9b. 

The digital signal-processing control unit is the link to the actuator subsystems and to external connections for operation switches. Usually, a 24-bit digital signal processor is used assisted by an ASIC for the fast Fourier transformation. Technical data of the sensor are as follows. 

Fig. 15 Eight-bit digital pneumatic microprocessor based on pneumatic Boolean logic circuit [55]. Reprinted with kind permission from [55] Copyright 2009 Royal Society of Chemistry...

In examining the above figures, one can spot the discrete increments both in conversion (calculated from real-time conductivity readings) and in temperature. Part of the visible scatter is due to the limited 12-bit digital resolution of the data acquisition system used. A more sophisticated data logging board will reduce this form of scatter. 

The problem is much more acute, however, for digitizing FID s of solid samples (without artificial, or other kinds of, narrowing) and the reason is two fold. First, fast ADC s are very much harder to make than slower ones. At the time of writing, there are new commercial modular units which convert analog signals into 8-bit digital words at 10 MHz at moderate (but not cheap) cost and the field is rapidly advancing. 

---