 Beakers of several sizes | |
| Uses | Liquid volume containment and measurement |
|---|---|
| Related items | Laboratory flask |
Inlaboratory equipment, abeaker is generally acylindrical 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 onemilliliter up to severalliters. A beaker is distinguished from aflask by having straight rather than sloping sides.[2] The exception to this definition is a slightly conical-sided beaker called a Philips beaker. Thebeaker shape in general drinkware is similar.
Beakers are commonly made of glass (today usuallyborosilicate glass[3]), but can also be in metal (such asstainless steel oraluminum) or certain plastics (notablypolythene,polypropylene,PTFE). A common use for polypropylene beakers isgamma spectral analysis of liquid and solid samples.
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 byJohn 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 decantingsupernatant 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, afterJöns Jacob Berzelius, and are mostly used fortitration.[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 awatch 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 oftengraduated, 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 (agraduated cylinder or avolumetric flask would be a more appropriate instrument for such a task), but rather an estimation. Most beakers are accurate to within ~10%.[6]
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 |
The dictionary definition ofbeaker at Wiktionary
Media related toBeaker (glassware) at Wikimedia Commons
