NESSLER TUBES

Nessler Tubes

In laboratories where colorimetric testing is performed, having optically uniform observation tubes is essential for achieving accurate, comparable, and reproducible results. Nessler tubes have been standardized as the ideal vessels for such tests, as they allow for clear observation of a solution’s color change against a visual standard or scale without interference.

At Pobel, we offer a line of Nessler laboratory tubes made from high-transparency glass, designed to meet the technical demands of analytical, quality control, environmental, food, and educational laboratories. Our priority is to provide every professional with a reliable, stable product compatible with widely used methodologies.

What Are Nessler Tubes?

Nessler tubes are glass cylinders, typically with flat bottoms and without graduations, used to hold solutions during colorimetric tests. Their design ensures direct visual reading or assisted comparison using devices, enabling the identification and quantification of dissolved substances — such as ammonia, iron, nitrites, chlorides, or metal compounds — through a reagent's color change.

The name derives from Nessler’s reagent, used to detect ammonia in aqueous solutions, although the use of the tubes has extended to numerous standardized colorimetric methods.

Key Technical Features

✔️ High-transparency optical glass: allows for clear readings with no unwanted refraction
✔️ Smooth, uniform walls: ensure sample consistency
✔️ Flat bottom: provides perfect stability on stands and analytical devices
✔️ Standardized dimensions: compatible with visual scales and photometers
✔️ Available in various capacities: commonly 50 ml and 100 ml

All models we offer are manufactured under strict quality standards, suitable for professional use in labs that demand reliability and repeatability.

Main Applications of Nessler Tubes

Nessler tubes are used to compare color and turbidity between solutions. They are often employed to prepare a series of calibration solutions with increasing concentrations, acting as a comparative scale. To minimize subjective perception differences in the color of the substance being analyzed, the tubes in a series must have identical characteristics: height, diameter, and glass thickness.

The American Public Health Association specifically mentions the 50 ml tube in the Standard Methods for the Examination of Water and Wastewater. The tubes are made of borosilicate glass 3.3, in accordance with USP Type I and ASTM E438 Type I, Class A requirements.

Advantages of Choosing Nessler Tubes from Pobel

At Pobel, we know that selecting the right tube is just as important as the analytical method itself. That’s why we offer:

✅ High-quality technical glass that meets required optical standards
✅ Guaranteed compatibility with comparator discs, standard color scales, and visual analysis kits
✅ Personalized guidance to help you choose the best model for each application
✅ Availability in multiple formats, with the option to purchase individually or in sets
✅ Support for laboratories, educational centers, and chemical analysis professionals

We are committed to delivering a reliable, durable, and technically accurate product so your lab can operate safely and efficiently.

Handling and Care: Best Practices

To extend the lifespan of Nessler tubes and ensure reliable results with each test, we recommend:

• Always handle tubes with clean gloves to avoid residues that may interfere with observation

• Wash with mild, non-abrasive detergents and rinse with distilled water after each use

• Air dry or use lint-free cloths, avoiding moisture buildup

• Store in stable tube racks, protected from dust and direct light

• Regularly inspect tubes for scratches or wear that could affect readings

Request Information About Nessler Tubes from Pobel

If you work with visual analysis and need a reliable, optically perfect tube compatible with your lab methods, Pobel is your professional partner.

Check availability, receive expert guidance, or place your order with total confidence.

Pobel: visual precision, guaranteed control.

Frequently Asked Questions

What is a Nessler Tube used for?
A standard Nessler tube, made from borosilicate glass with a stopper, is ideal for APHA color comparison due to its shadow-free bottom that transmits light without distortion. The stopper doesn’t need to be removed to take readings.