Linear expansion coefficient refers to the length of the glass changes with each degree change in temperature. The lower the linear expansion coefficient is, the greater the temperature change the glass can bear. The classification of laboratory glass is developed by USP (United States pharmacopoeia) according to its water resistance.
[USP TYPE 1, grade A, 33 borosilicate hydrochloride glass]
The most chemically inert glass is widely used in laboratories, especially for chromatographic analysis. Grade I glass is mainly composed of silicon and oxygen, containing trace amounts of boron and sodium, with the lowest solubility and linear expansion coefficient of 33.
[USP TYPE 1, class B, 51 borosilicate hydrochloride glass]
It consists mainly of silicon and oxygen, contains trace amounts of boron, sodium, and more alkali metals than grade A glass, but is still suitable for laboratory use. All brown glass is grade B glass with A linear expansion coefficient of 51.
Silanized or deactivated glass Borosilicate hydrochloric acid glass, which has been deactivated by organosilicon, has a highly hydrophobic and inert glass surface and is suitable for ph-sensitive compounds, trace analysis, and long-term sample storage.
[sample vial with screw orifice]
Provides bottom evaporation, reusable, hurt less than pliers flap competitors sealing way, without additional tools, thread cover sample vial in different specifications to distinguish, the specification defined by glass packaging association (GPI), thread samples of bottle mouth, such as 9-425 sample bottleneck is about 9 mm thread diameter, thread type for 425, thread sample vial mouth and the cover pad is higher than jaw vial price.
[screw head sample vial cap pad]
There is an open hole cover designed for automatic sample injection, a solid cover designed for sample storage, and an optional integrated PP cover. This piercable threaded cover is designed for a single sample injection and does not require cover pad assembly, which can save time for experiment preparation.
[sample vial with clamp]
Seal with aluminum cover, relatively cheap, when properly clamped, can be used for long storage to provide the best seal, clamps can not be reused, requires a greater force clamped.
[bayonet sample vial]
Seal with gland holder and remove gland holder from lid opener. It can be used together with a bayonet cap or bayonet cap. No tool is needed when using the bayonet cap. As its sealing property is not as good as that of a screw vial with clamps, it is recommended for short-time sample storage or non-volatile samples.