A burette is a uniform-bore glass tube with fine graduations and a stopcock at the bottom. It is used in volumetric analysis to measure the volume of a liquid, especially of one of the reagents in a titration. Burettes are used when it is necessary to dispense a small measured volume of a liquid, as for titration. Burettes may be used to calibrate the volumes of other pieces of glassware, such as graduated cylinders. Most burettes are made of borosilicate glass with PTFE (Teflon) stopcocks. Burettes are extremely accurate – a 50 cm3 burette has a tolerance of 0.1 cm3 (class B) or 0.06 cm3 (class A).The name Of apparatus used to hold burette is dropper clip.
Types of burettes:
1. Acid burette
2. Base burette
Difference between the both burette is that ACID burette can only take acid,and BASE burette can only take base.
Burettes measure from the top since they are used to measure liquids dispensed out the bottom. The difference between starting and final volume is the amount dispensed Also used for buretting are buretting syringes. These are calibrated to Volumetric A grade tolerances which are equal to or better than the traditional burette tolerance. The graduated buretting tube is provided with a thumb operated piston and PTFE seal which slide within the tube in a positive displacement operation. This arrangement is provided to achieve improvements in reliability, by removing problems of bubble entrapment while filling, leaks and blockages in stopcock mechanisms. The design also addresses handling safety, economy, and versatility when handling volumes between 0.5 and 25mL. The buretting syringe is set up in a traditional burette holder or used freehand. The positive displacement action enables it to handle any laboratory fluid – viscous and volatile, hydrocarbons, essential oils and mixtures, with great accuracy. Other features of the buretting syringe are the provision of a red line on the sliding seal which may be read instead of the meniscus, thus virtually eliminating parallax error, and its robust form which makes it more resistant to breakage and easier to clean.
1. It is used to to dispense a small measured volume of a liquid.
2. It is used for measuring liquid.
3. It is commonly used in titration.
4. It is used especially in laboratory procedures for accurate fluid dispensing and measurement.
Some burette manufacturers in India are:
1. Kshitij Innovations
2. Labtech International
3. Labtech International
4. Nexus Enterprises
5. Naugra Exports
6. Popular scientific