systems of measurement
DESCRIPTION
Systems of measurement. objectives. Apothecary system Metric system Abbreviations. Apothecary systems. Apothecary system is one of the oldest systems of measurement. Uses fractions, as opposed to decimals. Is less accurate than the metric system. Terminology. apothecary system. - PowerPoint PPT PresentationTRANSCRIPT
Systems of measurement
objectives
• Apothecary system• Metric system• Abbreviations
Apothecary systems
• Apothecary system is one of the oldest systems of measurement.
• Uses fractions, as opposed to decimals.• Is less accurate than the metric system.
Terminology
• the system used by an apothecary• a system of measurement used in
pharmacy prior to the metric system
• units of measure include minims, fluidrams, scruples, grains, ounces, and pounds
apothecary system
Apothecary Volume and Weight Equivalences
Apothecary Volume and Weight Equivalences
Apothecary Volume and Weight Equivalences
apothecary pound = 12 oz
household pound = 16 oz
Conversions between the Apothecary and the Metric
Systems
• Use equivalent measures to convert between units in the apothecary system.
• As a general rule, convert all quantities to the metric system as soon as possible.
Volume Equivalents
Volume Equivalents
There are actually 3.75 mL in 1 fluidram. However, convention dictates that 1 fluidram = 1 tsp = 5 mL.
Volume Equivalents
There are actually 29.57 mL in 1 fluidounce, but 30 mL is usually used
Weight Equivalents
Weight Equivalents
Many manufacturers use 60 mg instead of 65 mg as the equivalent for 1 grain.
Terminology
the smallest unit of measure in the apothecary system
grain
Conversions between the Apothecary and the Metric
SystemsConverting Grains
• The units of grains appears on nitroglycerin, along with milligram equivalent.
• Most pharmacists use 1 gr = 65 mg, but some sources indicate 1 gr = 60 mg.
Metric system
• Kg- Kilogram• L- Liter• mcg- microgram• mEq- milliequivalant• mg- milligram• mL- milliliter• μg- microgram• μgtt- micro drop• gm-gram
Safety Note!Many manufacturers use 60 mg instead of 65 mg as the equivalent for 1 grain. Read the label to confirm the package contents.
Conversions between the Apothecary and the Metric
SystemsConverting Fluidounces
Remember
16 fl oz = 480
1 fl oz = 30 mL
Lbs. to Kg
• There are two methods that may be used to convert pounds to Kg:
• Lbs./ 2.2 = Kg• Therefore, if you need to convert Kg to Lbs:• Kg x 2.2 = Lbs.
Metric Conversions
• Kg, g, mg, mcg• Lbs. to Kg• L to mL
Kg, g, mg, mcg
• To convert if going from large value to smaller value, move the decimal point 3 places to the right for each conversion.
• If going from smaller value to larger value, move the decimal point 3 places to the left for each conversion.
• 3.0 Kg = 3000. g = 3000 g• 3.0 Kg = 3000000. = 3,000,000 mg• 3.0 Kg = 30000000 00. =• 3,000,000,000 mcg
L to mL
• 1 L = 1000. = 1,000 mL• 500 mL = 500. = .5 L
Conversions to mg
• 300 mcg = 3 mg• 6 Kg = 6,000,000 mg• 14 g = 14,000 mg• 1,000 mcg = 1 mg
Conversions to mcg
• 1 g = 1,000,000 mcg• 0. 452 mg = 452 mcg• 0.010 mg =10 mcg• 0.0006 Kg = 600,000 mcg
Conversions to g
• 0.043 Kg = 43 g• 100,000 mcg =0 .1 g• 1,000 mg = 1 g• 0.075 mg =0.000075 g• 1,500 mcg = 0 .001500 g• 1 Kg = 1,000 g
Conversions to Kg
• 1000 g = 1 Kg• 1,500 mg = 0.0015 Kg• 0.042 mg = 0.000000042 Kg• 720,000,000 mcg = 0 .72 Kg
Lbs. to Kg
• 275 Lbs. = 125 Kg• 100 Lbs. = 45 Kg
Kg to Lbs.
• 100 Kg = 220 Lbs.• 32 Kg = 70 Lbs.
L to mL
• 2 L = 2,000 mL• 0.5 L = 500 mL• 1 L = 1,000 mL• 0.250 L = 250 mL
mL to L
• 3,000 mL = 3 L• 1,500 mL = 1.5 L• 500 mL = 0.5 L
mL v. cc
• A mL and a cc have the same value.• Therefore:• 1 mL = 1 cc• 500 mL = 500 cc• 0 .5 cc = 0.5 mL
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