Pen plotters

We have kept the data collection computer and its software simple and economical. The computing power and peripherals needed to provide high quality plotting and data reduction are available on a 32-bit minicomputer that supports a number of our projects. The floppy discs from the data collection process can be read directly into the data reduction computer. Special menus have been set up to facilitate plotting of the data on a high speed color raster display or on a high-quality multicolor pen plotter. 

An NMR spectrum is effectively a graph of the intensity of absorption of Rf radiation (y-axis) against the frequency of the Rf radiation (x-axis). Since frequency and magnetic field strength are linked by the Larmor equation, the x-axis could also be calibrated in units of magnetic field strength. In a CW NMR spectrometer, the x-axis of the output device (usually a pen plotter) is coupled to the frequency sweep so that the response of the sample is displayed as the frequency of the Rf transmitter varies. 

A hardcopy of your spectrum can be obtained using a pen plotter, an inkjet, or laser printer. There are a number of things you can include in your plot ... 

If the user wants to walk away with his graph, he needs some form of hardcopy unit. The nature (raster hardcopy, raster printer, or pen plotter) depends on his use for the copy. A screen copier might be used to produce suitable overheads for an informal presentation and a pen plotters output might be better for a speech given to a professional society or funding agency (they may be judged by the quality of his presentation as well as its content). 

The CRT displays are usually vector devices, usually of high resolution (1024 x 1024) to provide clean lines. Raster equipment with its lower resolution and "jaggies" does not provide any advantage until we add the complexity of the solid fill for surfaces, or a range of colors. Hardcopy - frequently pen plotters -is a normal requirement. 

J. Andrew McCammon holds the Joseph E. Mayer Chair of Theoretical Chemistry at the University of California, San Diego (UCSD), and is an Investigator of the Howard Hughes Medical Institute. He received his Ph.D. in chemical physics in 1976 from Harvard University, where he worked with John Deutch on biological applications of statistical mechanics and hydrodynamics. In 1976-1978, he was a Research Fellow at Harvard, where he developed the computer simulation approach to protein dynamics in collaboration with Martin Karplus. He was an Assistant Professor and then M.D. Anderson Professor (1981-1994) at the University of Houston before moving to UCSD. He recalls with pleasure the first views of atomic dynamics in a protein molecule, generated slowly on a pen plotter during his postdoctoral work. 

Specifications for the DSC7 are given in Table 6.7. As with the other DSC instruments, the data storage and processing is done by an external computer system with printout on a dot matrix printer or pen plotter, as discussed in Chapter IZ... 

FORMAT offers geometric transforms for translation and size rescaling. These are used to keep the structure properly placed within work area boundaries. The PLOT option directs structure output to a high resolution dot matrix plotting routine for printer output, or, optionally, to a pen plotter for high-quality drawings. 

Enable a pen plotter and provide proper serial interface parameters for the device. 

FIGURE 18.4 optimizing surfaces (a) a polygon filled by different vector widths (b) the same polygon as drawn by a pen plotter (c)the polygon as defined by its external outline. Option c is clearly much more efficient and economical. The outline in (c) is the actual outline of the polygon, whereas (a) and (b) represent approximations. 

Looking at the data given in SAQ 7.9, we should have guessed that the flow was not wholly laminar at 100 Hz because the error in the measurement starts to increase, i.e. there is more scatter and noise . With an RDE in front of us, we would have seen a vortex forming around the electrode, and a pen recording the current on an X-F plotter would be seen to judder and jump up and down in an unpredictable way. 

The last type of hard copy output device isn t really a printer at all. Printers make images one line at a time and move from top to bottom during the printing process. Plotters, on the other hand, draw the image as we would, with a pen. One shape at a time. Plotters are most often used with CAD software to produce blueprints or technical diagrams. It would be quite expensive to make a printer that can print on paper as wide as these drawings require. Because a plotter uses a pen (or several pens in a holder) on a cable carrier, it is easy (and relatively inexpensive) to make a very wide plotter. A couple of typical plotters are shown in Figure 6.18. 

D. Plotters draw the image with a pen one shape at a time and use CAD software to produce blueprints or technical diagrams. 

The first problem to be solved is that of man- nachine communication. Corey, Wipke and others have developed a system by which the chemist feeds in a structure by drawing a standard two-dimensional structural formula using an electrostatic tablet (Rand tablet) and a Rand pen. The computer communicates with the chemist by displaying conventional structural formulae on a cathode ray tube. Provision is also made for hard copy output using a plotter. As emphasized by Corey and Wipke 8.5) this allows for cui interactive relationship between the chemist and the computer. 

The load, as measured by the load cell, and the displacement, as measured by the LVDT, were recorded simultaneously on a two-pen recorder at all times. In addition, load versus displacement or load versus strain gauge output were recorded on an X-Y plotter. 

Figure 4.13 illustrates several techniques for patterning PEDOT PSS via electrochemical overoxidation. Conversion of a simple plotter pen or a screen-printing station are relatively straightforward, the latter allowing print resolution of a few hundred micrometers. To demonstrate that the technique is limited only by the resolution of the printing method, 2 p,m lines (the smallest mask available) were patterned in a 200 nm thick film with the aid of a photoresist mask [29]. 

FIGURE 4.13 Electrochemical overoxidation techniques for use with polythiophenes, (a) A plotter pen modified to be used in an electrochemical cell, (b) Screen-printing electrochemical cell, (c) Photoresist patterned on a PEDOT PSS film protects areas of the film from overoxidation whereas the rest is patterned when wet by the liquid electrolyte. (Images from Tehrani, P., Remonen, T., Hennerdal, L.-O., Hall, J., Malmstrom, A., Leenders, L., Kugler, T., Robinson, N.D., Crispin, X., Fahlman, M., and Berggren, M., Smart Mater Struct 14, N21-N25. Copyright 2005, Institute of Physics Publishing. With permission.)... 

Stepper motors are useful wherever accurate control of movement is required. They are used extensively in robotics and in printers, plotters and computer disk drives, all of which require precise positioning or speed. In a plotter, for example, by using two motors running at 90 degrees to each other, they can be used to drive a pen an exact distance in all directions. In robotics, they are used to position manipulators exactly where required. 

During the test, a two-pen X-Y plotter recorded strain gage output as a function offload. Our procedure was to load cycle the specimen (strain rate, e = 3 x 10 s ) to 25 to 35% of its ultimate strength four times with high sensitivity settings on the plotter these data yielded the elastic parameters. We decreased the plotter sensitivity on the final loading cycle to record the fracture parameters. 

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