Overview
ISO 4788:2005 is an international standard specifying the dimensions, materials, and metrological requirements for laboratory glassware-specifically graduated measuring cylinders. It covers two main cylinder forms, tall (Types 1a and 1b) and squat (Type 2), intended for general laboratory use. Compliant with the design principles in ISO 384, ISO 4788:2005 ensures uniformity in measurement accuracy and physical construction, addressing the demand for reliable volumetric measurement tools in various laboratory environments.
This standard introduces precision classifications (Class A and B), accommodates different working conditions including limited space, and outlines rigorous testing and marking requirements to guarantee quality and repeatability of measurements at a reference temperature of 20 °C (or 27 °C as applicable).
Key Topics
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Cylinder Types
- Type 1a: Tall form with a spouted neck for easy pouring
- Type 1b: Tall form with a stoppered neck for secure closure
- Type 2: Squat form with a spouted neck, suitable for space-constrained setups
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Accuracy Classes
- Class A: Higher accuracy for Types 1a and 1b, suitable for precision applications
- Class B: Lower accuracy for all cylinder types, including squat form (Type 2)
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Material and Construction
- Manufactured from hydrolytically resistant glass (minimum class HGB3 per ISO 719)
- Uniform wall thickness and robust construction to withstand normal laboratory use
- Stability ensured to prevent rocking or toppling even on inclined surfaces
- Fire-polished rims and well-shaped spouts to enable precise liquid handling
- Stoppered versions use standardized ground joints (ISO 383) with well-fitting stoppers
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Dimensions and Capacities
- Defined nominal capacities ranging from 5 ml up to 2000 ml
- Specific dimensional requirements including overall height, internal height, and graduation distances
- Graduation marks and subdivision patterns aligned with ISO 384 guidelines
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Metrological Requirements
- Maximum permissible errors vary by class and cylinder type, ensuring reliable volumetric readings
- Volumes referenced at standard temperatures for consistency (20 °C or 27 °C)
- Testing procedures in line with ISO 4787 ensure conformity to accuracy limits
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Marking and Identification
- Permanent markings include nominal capacity, unit, reference temperature, accuracy class, manufacturer, and type of glass
- Unique identification numbers for certifiable Class A cylinders or specific stopper-cylinders
- Clear, legible figures and graduation lines for ease of use
Applications
ISO 4788:2005 graduated measuring cylinders are essential instruments in various laboratory settings, including:
- Chemical Analysis: Accurate measurement and transfer of liquid reagents
- Quality Control: Volumetric verification in production and lab testing environments
- Pharmaceutical Labs: Precision dosing where high accuracy Class A cylinders are required
- Research and Development: Flexible cylinder options for different experimental setups
- Educational Laboratories: Reliable equipment for training in volumetric techniques
- Controlled Environments: Squat (Type 2) cylinders designed for usage in laminar flow cabinets, glove boxes, and fume hoods where vertical space is limited
The standard ensures compatibility with existing volumetric glassware practices and facilitates accreditation by meeting globally recognized quality benchmarks.
Related Standards
- ISO 384: Principles of design and construction of volumetric glassware-provides foundational guidelines followed by ISO 4788
- ISO 719: Test methods for hydrolytic resistance of glass grains-ensures durability and chemical stability of cylinder glass material
- ISO 4787: Methods for use and testing of capacity in laboratory volumetric glassware-sets procedures for accuracy verification
- ISO 383: Interchangeable conical ground joints for laboratory glassware-relevant for stoppered Type 1b cylinders requiring standardized connections
- ISO 4794: Assessment methods for chemical resistance of enamels used in marking-supports durability of cylinder markings
By adhering to ISO 4788:2005 and associated standards, laboratories and manufacturers guarantee precision, durability, and usability of graduated measuring cylinders crucial for safe and effective volumetric measurements worldwide.
