Because dry volume is based on inches and centimeters there is no effect on accuracy of cubic measurements.
For weight measurement 1 pound Avoirdupois = 7000 grains = 453.59237 grams EXACTLY so there is no effect on accuracy.
Since the metric system defines 1 milliliter as 1 cubic centimeter of water at Standard Temperature and Pressure (STP) and gives it a weight of 1 gram, there is no effect on accuracy there either.
Of course, the smaller your increments of measurement, the more precise your measurement. But precision is not the same as accuracy.
Also, the conversion from Fahrenheit to Celcius = degrees F - 32 x 5/9 and from Celcius to Fahrenheit = degrees Celcius x 9/5 + 32 so accuracy is the same there also.