It is sold by mass, normally grams and ounces. While I don't know the precise limit, it is too viscous to be sold by volume. It would have to self-level in a tolerable time in a precision volumetric flask. Honey is usually sold by mass, but pancake syrup by volume, so that is approximately the viscosity range for the transition.
________________________________ From: John Frewen-Lord <[email protected]> To: U.S. Metric Association <[email protected]> Sent: Tue, May 3, 2011 11:31:22 AM Subject: [USMA:50417] Re: Conversion vs. Substitution (formerly hard vs. soft conversions) Interesting that you used toothpaste as an example. Everywhere I've seen (especially, UK, Canada, Australia, EU), toothpaste is sold in mL, not g. Is toothpaste sold by mass in the US, not volume? Or is that 'oz' number a shortened version of floz? Again, another reason to dump that old collection of disparate measuring units. John F-L ----- Original Message ----- >From: Ressel, Howard (DOT) >To: U.S. Metric Association >Sent: Tuesday, May 03, 2011 4:19 PM >Subject: [USMA:50416] Conversion vs. Substitution (formerly hard vs. soft >conversions) > > >Now that the new American National Standard for Metric Practice, dated April >11, >2011, commonly referred to as SI-10 has been published, I want to share one of >the newer concepts that was included in the appendix to the document. When >our >office started to convert, we underwent much training and learned the terms >hard >and soft conversion. It was the hardest concept to teach and many of my >colleagues often mixed them up. I came up with a new terminology which seems >to >be more logical, that of conversion vs. substitution. > >Transitioning from traditional inch-pound units to SI requires changing >quantity >values from one system to another. This can be done by direct conversion >(formerly soft conversion), using commonly published and defined factors to >multiply the inch-pound unit to an SI value. For example, 7 feet converts to >2.1 >m. The rules for rounding and accuracy should be appropriately applied >depending >on the application. The choice of conversion units would also be dependent on >the need. A scientist or engineer may use a universally accepted standard >conversion factor found in a standard such as SI-10, a homeowner converting a >number to measure a room to purchase a carpet might look up a number on the >internet or a textbook. The concept is still the same; conversion is the >direct >mathematical equivalent of the number in the other units. > >The other transition method uses substitution (formerly hard conversion). In >substitution, a new rational metric size is used for the value of the >measurement for the item being converted. While conversion maintains the >original standard value, substitution defines a new standard value for the >measurement. Substitution should not be confused with rounding. Substituted >values can be defined in many ways. It may be set by a national or >international >standard organization. There might be a causal substitution, for example that >of a small manufacturer deciding to package products in 0.5 l jars instead of >20-ounce jars. > >Whereas conversion will generally accommodate full compatibility between >existing and new items, substitution may require modification or transitions >for >compatibility to occur. Ideally, substitution would be used for every product >we >purchase or use but compatibility issues, tradition and costs will probably >require conversions for years to come. One quick example, a 4.5 oz tube of >toothpaste sold as a 125 g tube is a substitution, toothpaste sold, as a 127.6 >g >tube is a conversion. Generally, conversion should be used when items must fit >together and not all the standards have been changed, but substitution should >be >used when the entire item can be specified in a new rational manner. >The terms conversion and substitution should be used to clarify between a >direct >conversion of a measurement and the choice of a new rational size for an >object >or value. The older terms hard conversion and soft conversion should no longer >be used. > > > > > >Howard Ressel >Project Design Engineer >NYSDOT >1530 Jefferson Road >Rochester, NY 14623 >585 272-3372 >
