Scientific balances and scales are usually categorized according to their readability:

• Industrial scales and balances (1-0.1g)
• Precision balances (0.01-0.001g / 10-1 mg)
• Analytical balances (0.0001 g / 0.1 mg)
• Semi-micro balances (0.00001g/ 0.01 mg)
• Micro balances (0.000001g / 1 μg)
• Ultra-micro balances (0.0000001g / 0.1 μg)

Units of measure:  g = gram | mg = milligram |  μg = microgram