Difference Between

32 Difference Between Volumetric and Mohr Pipettes

32 Difference Between Volumetric and Mohr Pipettes

Laboratory glassware such as volumetric and Mohr pipettes are used to measure and transfer liquids precisely. Although they are made differently and have different functions, they are both intended to dispense precise amounts of liquids.

Glassware used in laboratories to measure and transmit a precise volume of liquid is called a volumetric pipette. Their purpose is to provide a precise volume of liquid at a given temperature in a single serving. In analytical chemistry, pharmaceutical labs, and other scientific fields where accurate measurements are essential, volumetric pipettes are frequently utilized

It’s crucial to understand that volumetric pipettes differ from other kinds of pipettes, including graded or micropipettes, which have different levels of precision and are intended for distinct uses.

It is imperative to adhere to appropriate laboratory practices when handling, cleaning, and calibrating volumetric pipettes in order to guarantee precise and trustworthy outcomes for scientific investigations and evaluations.

A Mohr pipette is a type of graduated pipette used in analytical chemistry to measure and transfer a specified volume of liquid with great accuracy. It is sometimes referred to as a Mohr burette or Mohr’s burette. It bears the name Karl Friedrich Mohr in honor of the German scientist who made significant contributions to the advancement of analytical methods during the 1800s.

It’s important to remember that using Mohr pipettes correctly is essential to ensuring precise measurements. This entails letting the liquid drain entirely and taking an accurate reading of the volume at the meniscus. Consistent calibration and upkeep are also required to guarantee the pipette’s accuracy throughout time.



Volumetric Pipettes

Mohr Pipettes



Used for precise measurement of a specific volume of liquid

Used for approximate measurement of variable volumes of liquid



Generally have a single graduation mark

Have various calibration marks for different volumes



Used for fixed volumes, usually between 1 mL to 100 mL

Have a variable capacity, commonly used for 1 mL or less



Bulbous at the top with a long tube and a sharp tip

Straight design with a constriction near the top



Higher accuracy and precision with lower tolerance

Tolerance may be higher due to the variable nature of measurements



Precise measurement of fixed volumes

Less precise due to the potential for variable measurements



Commonly used in analytical chemistry and pharmaceutical labs

Often used in educational settings or for general qualitative analysis



Requires careful handling and technique to ensure accuracy

Relatively easy to handle and use



Often cleaned using specific procedures to maintain accuracy

Can be cleaned using standard laboratory cleaning procedures



Calibrated for a specific volume at a particular temperature

Calibrated for general measurements within a certain range



Made of high-quality glass for precise measurements

Typically made of standard laboratory-grade glass



Relatively expensive due to higher precision

Less expensive compared to volumetric pipettes



High accuracy due to fixed volume measurements

Relatively lower accuracy compared to volumetric pipettes


Filling Method

Often used with a pipette filler or bulb for controlled filling

Typically filled using a rubber bulb or pipette filler



Requires thorough rinsing to ensure accurate measurements

Requires rinsing but not as critical for accuracy



Offers high reproducibility for the same volume

Reproducibility may vary due to the nature of variable measurements



Low variability in the measurements

Higher variability in the measurements due to design


Error Margin

Lower error margin due to precise calibration

Higher potential for error due to variable measurements


Usage Limitation

Not suitable for measuring variable volumes

Suitable for measuring variable volumes within a certain range


Common Sizes

Common sizes include 10 mL, 25 mL, 50 mL, and 100 mL

Commonly available in sizes up to 1 mL



May require specialized sterilization procedures

Can be sterilized using standard laboratory methods


Viscous Liquids

Not suitable for highly viscous liquids

Suitable for handling moderately viscous liquids


Sample Volume

Used for accurate measurement of specific sample volumes

Used for approximate measurement of sample volumes


Technique Sensitivity

Sensitive to the technique used for filling and dispensing

Less sensitive to the technique used for handling



Includes various types like Class A, Class B, and disposable types

Generally available as a single type with variations in size


Meniscus Reading

Read at the bottom of the meniscus for accurate measurements

Read at the top of the meniscus for approximate measurements


Quality Control

Strict quality control measures to ensure accuracy

Quality control measures are relatively less stringent


Regulation Compliance

Often used for regulated measurements and experiments

Used for general purposes and educational settings



Follows specific standardization procedures

Follows general standardization guidelines


Liquid Transfer

Primarily used for precise liquid transfer

Used for transferring liquids with less emphasis on precision


Error Handling

Errors can be minimized with proper technique and handling

Errors are less critical due to the approximate nature of measurements


Calibration Standards

Subject to strict calibration standards for accuracy

Calibration standards are relatively less stringent compared to volumetric pipettes

Frequently Asked Questions (FAQ’S)

Q1. What distinguishes a volumetric pipette from other kinds of pipettes?

Volumetric pipettes are highly accurate in delivering a precise volume, unlike graded pipettes that can dispense variable volumes. Critical measurements are usually performed with volumetric pipettes.

Q2. How is a volumetric pipette used?

Using a pipette filler, you draw the liquid into the volumetric pipette and let the excess liquid drain after rinsing it with the liquid to be measured. The pipette’s calibrated volume is exactly the final volume.

Q3. What role does calibration play in volumetric pipettes?

The volumetric pipette’s accuracy is guaranteed by calibration. It entails figuring out the precise volume the pipette delivers in certain circumstances. To keep measurements accurate, regular calibration is required.

Q4. Is it possible to utilize a volumetric pipette in place of a Mohr pipette?

No, they aren’t compatible with one another. Mohr pipettes are appropriate for less important measurements where a slight variation in volume is acceptable, whereas volumetric pipettes are made for accurate volume delivery.

Q5. Are there any particular safety measures to follow when utilizing Mohr and volumetric pipettes?

Take caution when handling both kinds of pipettes to prevent breaking them. Make sure the liquid is fully drained before using a volumetric pipette to get precise measurements. Observe the safety regulations in the lab.

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