Transparent material… Water vapor measurement… Digital recording…
Dear Search Engineer: I am looking for a window screen material that is highly transparent, and nearly invisible. It will be used in a luxury recreational vehicle for the screen door on the entry door. Our current door screen limits the visibility for the passenger and at times, due to light conditions, the driver's vision is also impaired. The shape of the door doesn't lend itself to a rollup or removable screen, so that is probably not an option. Gore-tex makes a material that might work, but at this time it has an exclusive relationship with Pella windows and isn't available for other manufacturers to use. Any suggestions? — J.J., Junction City, OR
Dear J.J.: Investigate partial metallization of the window itself. It will not affect driver vision, i.e. light entering, but impairs light's escaping. It is also the principle behind one-way mirrors. Be careful, however, as a mirror might cause blinding of other drivers when reflecting sunlight or bright headlights. Slight tilting of the glass will help reflect the incoming strong light downwards, away from other drivers.
Dear Search Engineer: I am looking for an instrument that will allow me to measure the amount of water vapor in a low pressure (0.2-2 torr) nitrogen stream. I do not want to pay for a residual gas analyzer system. Any suggestions?— J.F., DN reader
Dear J.F.: One reader suggests that a fairly inexpensive but reliable instrument is the Vaisala digital dewpoint meter model DM70 with the DMP74B and the DSC74 sampling cell to connect to your piping. The conversion from dewpoint to PPMv and/or absolute moisture is available on the Internet, or log onto http://www.drytechinc.com and look at the data tables there to see your gm/m3.
Dear Search Engineer: I would like to measure the digital strength of each finger in grams and have it displayed and recorded in a computer. Any idea how to go about doing this? — M.N., DN reader
Dear M.N.: One reader suggests using some self stick pressure sensors such as the SF-2 from CUI (http://www.cui.com). Initially developed for robotics artificial skin, they are available from DigiKey and are quite cheap.
Dear Search Engineer: I need a permanent self-sticking laser printable label material with a tough clear outer layer to print labels with the company name, a logo, bar codes, and alphanumerics. I want to replace the engraved metal labels that are riveted to a product with something like the above that has comparable or superior durability. Any suggestions? — L.W., DN reader
Dear L.W.: Several readers weighed in on this question. 3M (www.3m.com) makes several polyester labelstocks with paper liners that are designed to be used in desktop laser printers. 7842TL, 7845TL, 7850TL are all available, each with a different adhesive. These adhesives are designed give adhesion to a range of surfaces so it is important to know what surface you plan to use to attach the label. MARKEM Corp. (www.markem.com), in Keene, NH, and another company, called Zebra (805-578-7199), also may be good sources.