Measuring Pipettes

Measuring pipettes are available in classes A, AS, and B and are adjusted to Ex. A distinction is made between measuring pipettes for partial drainage (calibration numbering from top to bottom) and those for complete drainage (calibration numbering from bottom to top).

Below is a brief description of handling both types of measuring pipettes regarding filling and emptying.

Measuring Pipettes for Partial Drainage

Filling

• Check the pipette (it must be clean and free of grease, the tip must be intact).
• Aspirate liquid with a pipetting bulb to approximately 10 mm above the zero mark.
• Wipe the outside of the pipette, hold it vertically at eye level, place the outlet tip against the inner wall of a glass vessel, and adjust the meniscus to the zero mark. Wipe the pipette on the vessel wall.

Emptying

• Hold the pipette vertically, place the outlet tip against the inner wall of a glass vessel, and allow the contents to drain to approximately 10 mm above the desired mark (for class AS: observe a waiting time of 15 seconds!).
• Adjust the meniscus to the desired mark at eye level.

Measuring Pipettes for Complete Drainage

Filling

• Check the pipette (it must be clean and free of grease, the tip must be intact).
• Aspirate liquid with a pipetting bulb to approximately 10 mm above the desired mark.
• Wipe the outside of the pipette, hold it vertically at eye level, place the outlet tip against the inner wall of a glass vessel, and adjust the meniscus to the desired mark. Wipe the pipette on the vessel wall.

Emptying

• Hold the pipette vertically, place the outlet tip against the inner wall of a glass vessel, and allow the contents to drain.
• 3 seconds after the completion of continuous drainage, once a permanent meniscus has formed in the pipette tip, wipe the pipette on the vessel wall (for class AS: observe a waiting time of 15 seconds!).

Measuring Cylinders

Measuring cylinders are made of glass and various plastics. They range in capacity from 5 ml to over 2 l. Most have a spout to facilitate pouring. Mixing cylinders have no spout and are only suitable for mixing liquids.

There are three designs: tall form with spout, tall form with stopper, and low form with spout. The base is hexagonal or round. Cylinders with stoppers have a ground neck at the upper end on the inner wall. Volume measurement involves counting the line or ring. Start at the base and count up to the nominal volume. Cylinders are made from high-quality plastic or DURAN borosilicate glass.

Accurate Volume Measurement

The scaling of measuring and mixing cylinders is very precise. There are two accuracy classes for DURAN products. The two classes have different tolerances. Class A is the highest accuracy class. Class AS has the same tolerances as Class A but shorter drainage times. Class B has twice the error of Class A. Measuring and mixing cylinders are calibrated to "in". When the ring mark is reached, the exact amount of liquid specified is in the vessel. This allows precise adjustment of the desired concentration.

Notes on Heating Laboratory Glass Volume Measurement Devices

Devices should not be heated above +180 °C to ensure long-term durability and prevent volume loss. Heating plates are not ideal. It is better to heat and cool volume measurement devices slowly to prevent stress and glass breakage.

Plastic Measuring Cylinders, Measuring Flasks, and Mixing Flasks

Häberle also offers products made from PP and PMP plastics. Measuring cylinders are manufactured according to DIN 12 681 and ISO 6706. They are each adjusted to "in". PP can withstand temperatures up to 80 °C without permanent errors. However, the graduation is preserved only if the device is not cleaned above 60 °C.

For PMP, Brand states that autoclaving at temperatures up to 121 °C does not cause permanent errors. Cleaning should not exceed 60 °C to preserve the graduation. If you frequently autoclave the measuring cylinder, choose one with raised graduation.

There are PP measuring cylinders in tall and low forms. There are normal and raised graduations. PMP measuring cylinders are only available in tall form. Here too, there are cylinders with normal and raised graduations. If you wish, we can provide you with a batch certificate for Brand PMP measuring cylinders.

SAN measuring cylinders are crystal clear and calibrated to "in". Tolerances correspond to Class B according to DIN 12681 and ISO 6706. These parts can withstand temperatures up to 60 °C without altering tolerances. The scale is raised on these products. SAN measuring cylinders are available in tall and low forms. The former have a hexagonal base.

Measuring Flasks

Measuring flasks made of borosilicate glass with standard ground joints. They are also called volumetric flasks. They are needed to precisely prepare concentrations of solutions. Measuring flasks are the most accurate volume measurement devices in the laboratory. They are used to prepare standard solutions or dilute solutions.

Brand measuring flasks are made of glass and undergo quality control. If desired, you can get Brand measuring flasks with a PP stopper with a tip. These stoppers prevent the measuring flask from rolling off the lab bench. Additionally, BLAUBRAND measuring flasks from Brand are delivered with batch number and batch certificate. Upon request, they are also available with individual certificate or DAkkS calibration certificate. The wide neck version has a USP individual and batch certificate.

Vitlab's measuring flasks are available in PMP, PFA, and PP materials. All plastics are highly transparent and available in accuracy classes A and B (according to DIN EN ISO 1042). The ring mark is individually adjusted to "in". To protect the printing, cleaning at a maximum of 60 °C is recommended. Vitlab's PP measuring flask withstands temperatures up to 60 °C. PFA and PMP flasks can be autoclaved up to 121 °C. Consider the different chemical resistances of the materials. You can also obtain a DAkkS calibration certificate or individual certificate.

Manufacturers We Offer

• BRAND
• Hirschmann
• ISOLAB
• LLG
• Vitlab
• The nails
• Duran