I think there's some interesting sociology / anthropology tied up in this.
Reading through the MA regs, it looks like they primarily regulate:
-- Scales of all kinds
-- Volumetric measurements for petroleum products and dairy products
-- Taxi meters
-- other commerce tools (grocery store scanners, change machines, bottle/can refund machines, etc)
It's a truism that weight is a much more accurate way to specify products than volume, which is why even liquids like self-serve soup at the grocery store are sold by mass, not volume.
However, we are historically used to buying gasoline, milk and ice cream by the gallon or liter, not the pound or kilo. It's also interesting that milk and ice cream are the fluids mentioned besides petroleum products in the state code -- we give dairy products a very special place in our culture. In Massachusetts, a 1967 law actually makes it illegal for stores to give away free milk!
Reading through the MA regs, it looks like they primarily regulate:
-- Scales of all kinds -- Volumetric measurements for petroleum products and dairy products -- Taxi meters -- other commerce tools (grocery store scanners, change machines, bottle/can refund machines, etc)
It's a truism that weight is a much more accurate way to specify products than volume, which is why even liquids like self-serve soup at the grocery store are sold by mass, not volume.
However, we are historically used to buying gasoline, milk and ice cream by the gallon or liter, not the pound or kilo. It's also interesting that milk and ice cream are the fluids mentioned besides petroleum products in the state code -- we give dairy products a very special place in our culture. In Massachusetts, a 1967 law actually makes it illegal for stores to give away free milk!