Glass container used in laboratories
Beaker
Beakers of several sizes
|
Uses
| Liquid volume containment
and measurement
|
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Related items
| Laboratory flask
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In
laboratory equipment
, a beaker is generally a
cylindrical
container with a flat bottom.
[1]
Most also have a small spout (or "beak") to aid pouring, as shown in the picture. Beakers are available in a wide range of sizes, from one
milliliter
up to several
liters
. A beaker is distinguished from a
flask
by having straight rather than sloping sides.
[2]
The exception to this definition is a slightly conical-sided beaker called a Philips beaker. The
beaker shape in general drinkware
is similar.
Beakers are commonly made of glass (today usually
borosilicate glass
[3]
), but can also be in metal (such as
stainless steel
or
aluminum
) or certain plastics (notably
polythene
,
polypropylene
,
PTFE
). A common use for polypropylene beakers is gamma spectral analysis of liquid and solid samples.
Construction and use
[
edit
]
Standard or "low-form" (A) beakers typically have a height about 1.4 times the diameter.
[3]
The common low form with a spout was devised by
John Joseph Griffin
and is therefore sometimes called a Griffin beaker.
[4]
[5]
These are the most universal character and are used for various purposes?from preparing solutions and decanting
supernatant
fluids to holding waste fluids prior to disposal to performing simple reactions. Low form beakers are likely to be used in some way when performing a chemical experiment. "Tall-form" (B) beakers have a height about twice their diameter.
[3]
These are sometimes called Berzelius beakers, after
Jons Jacob Berzelius
, and are mostly used for
titration
.
[5]
Flat beakers (C) are often called "crystallizers" because most are used to perform crystallization, but they are also often used as a vessel for use in hot-bath heating. These beakers usually do not have a flat scale.
The presence of a spout means that the beaker cannot have a lid. However, when in use, beakers may be covered by a
watch glass
to prevent contamination or loss of the contents, but allowing venting via the spout. Alternatively, a beaker may be covered with another larger beaker that has been inverted, though a watch glass is preferable.
Beakers are often
graduated
, that is, marked on the side with lines indicating the volume contained. For instance, a 250 mL beaker might be marked with lines to indicate 50, 100, 150, 200, and 250 mL of volume. These marks are not intended for obtaining a precise measurement of volume (a
graduated cylinder
or a
volumetric flask
would be a more appropriate instrument for such a task), but rather an estimation. Most beakers are accurate to within ~10%.
[6]
Standards
[
edit
]
DIN EN ISO 3819:2015-12 defines the following types and sizes:
[7]
Type
|
Nominal volume
(ml)
|
Outer diameter
(mm)
±5%
|
Overall height
(mm)
max.
|
Wall thickness
(mm)
min.
|
Low high beaker
|
5
|
22
|
32
|
0.7
|
|
10
|
26
|
37
|
0.7
|
|
25
|
34
|
52
|
0.7
|
|
50
|
42
|
62
|
0.8
|
|
100
|
50
|
72
|
0.9
|
|
150
|
60
|
82
|
1.0
|
|
250
|
70
|
97
|
1.1
|
|
400
|
80
|
113
|
1.2
|
|
500
|
85
|
118
|
1.3
|
|
600
|
90
|
128
|
1.3
|
|
800
|
100
|
138
|
1.3
|
|
1000
|
105
|
148
|
1.3
|
|
2000
|
130
|
188
|
1.4
|
|
3000
|
150
|
214
|
1.7
|
|
5000
|
170
|
274
|
2.0
|
|
10000
|
220
|
360
|
2.0
|
|
|
|
|
|
High beaker
|
50
|
38
|
72
|
0.8
|
|
100
|
48
|
82
|
0.9
|
|
150
|
54
|
97
|
1.0
|
|
250
|
60
|
123
|
1.1
|
|
400
|
70
|
133
|
1.2
|
|
500
|
79
|
140
|
1.3
|
|
600
|
80
|
153
|
1.3
|
|
800
|
90
|
178
|
1.3
|
|
1000
|
95
|
183
|
1.3
|
|
2000
|
120
|
244
|
1.4
|
|
3000
|
135
|
284
|
1.7
|
|
5000
|
160
|
324
|
2.0
|
|
|
|
|
|
Thick wall type
|
150
|
60
|
82
|
1.11
|
|
250
|
70
|
97
|
1.2
|
|
400
|
80
|
111
|
1.4
|
|
600
|
90
|
127
|
1.4
|
|
1000
|
105
|
147
|
1.4
|
|
2000
|
132
|
187
|
1.5
|
|
5000
|
170
|
275
|
2.5
|
See also
[
edit
]
References
[
edit
]
Further reading
[
edit
]
- ASTM
E960 - 93 (2008)
Standard Specification for Laboratory Glass Beakers
External links
[
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]
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Control devices
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Measurement
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Tools
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