How to Use an Analytical Balance
How to Use an Analytical Balance
Learn how to use an analytical balance. In this video, we’ll explore the steps and techniques required to set up, take measurements, and clean the balance.
To find a life science course near you, visit http://www.ncbionetwork.org.
Filmed on location at Gaston College.
Special thanks to:
Toby Mapes
Randy Durren
Joe Issa
Written and Produced by:
Dan McClellan
Production Team:
Vidmuze ( / vidmuze )
Mike Gentilini, Jr.
Ryan Atkins
Grant Pauley
Copyright © 2017 NC Community Colleges and BioNetwork
Content
6.97 -> One of the most commonly used pieces of equipment in biotech laboratories is
11.98 -> called an analytical balance. We can use
it to take very precise measurements...
17.53 -> four places to the right of the decimal point. Keep in mind that a small paperclip
22 -> weighs about one gram. In other words the analytical balance isn't designed for
27.22 -> weighing heavy items. For example, this
balance has a maximum weight of 310
33.25 -> grams. That's about the same weight as a
can of tomato soup. Weighing anything larger
38.739 -> than that will cause damage. The first
consideration is selecting the workspace.
43.629 -> The balance needs to be placed on a
steady surface such as a marble counter
48.699 -> or a lab workbench in order to minimize
vibrations. The balance shouldn't be used
53.89 -> near doorways or air vents because it's
sensitive enough to be affected by air
58.42 -> currents. Check to see if the balance is
level. Adjust the feet until the air
63.699 -> bubble is inside the black ring. If the
balance has been unplugged or turned off
69.79 -> you need to let it warm up and reach the
required operating temperature. Let's try
76.12 -> an example. We want to measure out 1.5
grams of sodium bicarbonate. Typically we
82.69 -> use weighing paper for measuring anything less than 5 grams. Fold the opposite
87.55 -> corners of the weighing paper together
and make a crease. Then do the same for
91.93 -> the other corners. Place the paper on the
balance pan. Close the side doors and
97.42 -> press the tare button to zero out the
paper. Use a lab scoop to slowly add the
104.53 -> sodium bicarbonate to the paper. Close
the glass doors and wait for the balance
110.17 -> to lock in its reading. Continue adding sodium bicarbonate until
116.069 -> you reach 1.5 grams.
Close the doors to read the actual
120.119 -> weight. 1.5026 grams - and always
document your work in your lab notebook.
128.84 -> Let's do another example. This time we'll
weigh something a little heavier so
134.34 -> we'll use a weigh boat instead of paper.
Let's measure out 12.19
138.989 -> grams of powdered Tris buffer. Place the
weigh boat on the balance pan. Close the side
145.11 -> doors and press the tare key. We're
aiming for 12.19 grams
151.47 -> so the measurement should be within plus
or minus 0.02 grams. Always document your
160.349 -> work in your lab notebook. Cleaning the
balance is an important step, especially
166.47 -> at the end of the day. Put it into
standby mode or unplug it. Remove the weigh
171.54 -> pan and components by lifting straight
up.
184.2 -> Use a very soft bristle paintbrush to
sweep off any powder remaining inside
189.51 -> the weigh chamber and in the grooves for
the glass doors. Once it's clean, replace
194.459 -> the drip ring and the weigh pan.
215.34 -> Now you're ready to head into the lab
and practice using an analytical balance
219.44 -> hands-on. To find in life science course
near you visit nccommunitycolleges.edu
226.44 -> or ncbionetwork.org.
Source: https://www.youtube.com/watch?v=mmgiehwrK54