Pete, that's the same chart I came across recently when looking for capacities of the different size mixers. Thanks! Then I was a bit confused about their use of absorption rate in the chart and how that related to my dough's hydration. In turn where my dough falls on the chart. Maybe you or someone else can explain that a little better to me.
The absorption ratio as referenced in the notes at the botton of the first page of the Hobart document at http://www.hobartfood.com.au/resources/brochure/Mixer%20Capacity%20F-7701(9-05).pdf
is basically a hydration value. I believe that it it possible that that number is the rated absorption value of a flour as specified by the miller. For example, if you read the opening post at http://www.pizzamaking.com/forum/index.php/topic,4646.msg39204.html#msg39204
, you will see the rated absorption values for three of the King Arthur flours. Most millers--and that includes General Mills--do not publicize the rated absorption values for their flours but they may provide the numbers upon specific request. As a practical matter, most rated absorption values are pretty close to what one might actually use as hydration values in practice. In relation to the absoption ratio, the Hobart notes make mention of a flour moisture of 12%. As you may know, in the U.S., most basic white flours have a moisture content of around 14% at the miller's facility. However, by the time it emerges at the tail end of the distribution channel, the moisture content can be around 12%. It would be highly unlikely under normal conditions for the moisture content to drop much below 12%. What all of this means is that there may be a need to tweak the hydration value of a dough to compensate for the altered moisture content of the flour.
The Hobart notes also mention the need to reduce the dough batch size by 10% if high gluten flour is used. Moreover, as the notes also say, one shouldn't use the second mixer speed for a dough with an AR of below 50%. Unless you plan to use high gluten flour and/or a dough with a hydration value of below 50%, then neither of these admonitions will apply to you.
The bottom line is that you should treat the AR value as essentially synonymous with the hydration value you plan to use but be prepared to make minor adjustments to the dough because of the flour's moisture content, and to adjust the dough batch size if you decide to use high gluten flour, in which case you would use only the first mixer speed.