Regarding my sugestion to legslate that all MEASURING DEVICES must be marked both in metric and non-metric or be switchable between metric and non-metric, James R. Frysinger wrote: > ...my Reallygood Raisin > Scoop ... now you tell me that I've got to > mark it in SI units.
No. A raisin scoop is a scoop, not a measuring device. Besides, any such law waould not apply retroactively to items already manufactured (and perhaps not to any that are "in the pipeline"); only new ones. > What about people who market ring gauges for jewelry? How about thread > gauges -- Yes, NEW ring gauges and thread gauges would need to be in both. Here are examples where, perhaps, dual marking would mean metric on some and non-metric on others IN THE SAME SET. That would satisfy my idea of a measuring device that could measure in either system. The "measuring device" would consist of an entire set. The law would have to be carefully written to accommodate such variations inmeaning. > ... does that mean that all threaded fasteners now must be rated > in metric units, even non-metric fasteners? Of course not. Threaded fasteners are not measuring devices. > How about those measuring > sticks used by lumbermen to estimate the number of board-feet in a log? > ... SI 10 (says) that the definition of a board foot > used nominal and not actual measurements. Sounds to me like this is not an actual measuring device either. If these problematic examples are too numerous to make special "exceptions" in the legislation to accommodate all of them, perhaps the solution is to specify those few things which ARE covered, rather than say "all" and then have to accommodate many special cases. I would cover all general purpose measuring devices (not those designed for measuring one specific case like the "number of board-feet in a log" rods). It would include: all measuring rods and tapes (ordinarily called yard sticks and metre sticks, foot rules and 25 cm rules, etc.); all thermometers (air temperature, body temperature, oven temperature, pool thermometers, etc.); all scales for weighing mass or weight or both* (for body mass, grocery items, truck load limits for vehicles, etc.); all volume measuring devices (including graduated kitchen measuring cups, gasoline dispensing pumps, etc.); pressure measuring devices (tire pressure gauges, barometers, blood pressure machines, etc.). Needless to say, it is not necessary to worry about voltmeters, ammeters, ohmeters, and watt-meters but we might need to include kilowatt-hour meters. In all this, I am talking about requiring that NEWLY manufactured and sold measuring devices meet the new requirements, not that everyone would have to throw out all their old ones. Since there are so many old, non-metric devices extant, we might even require that all new ones must be either dual or ALL METRIC. Why not? Regards, Bill Hooper college physics teacher (retired), USA (Florida) * A scale can be made to measure either mass or weight or both on the same scale at the same time. Since in older non-metric measures it is usually the weight in pounds that is nesired while in SI it is usually the mass in kilograms that is desired, an exception could be made for scales that would allow the non-metric readout to state the weight in pounds (or lbs & oz) while the metric readout would be allowed to specify the mass in kilograms. Any gven number of pounds always has the same number of kilograms of mass IF we remain in the same gravitational conditions (e.g. on surface ot planet Earth) and IF we do not require extreme accuracy (only to the nearest quarter pound or tenth of a kilogram). Both conditions are expected for most such devices described here. Of course, one COULD perhaps have a quadruple scale (or 4-way readout) giving weight in pounds and newtons and mass in slugs and kilogram, letting the user ignore all those that he/she is not interested in. +-+-+-+-+-+-+-+-+-+-+-+ Do It Easy, Do It Metric! +-+-+-+-+-+-+-+-+-+-+-+
