Length Comparator with Mechanical Dial Indicator

Length Comparator with Mechanical Dial Indicator

Length Comparator

The Length Comparator is a precision instrument designed for accurately measuring length changes in 10in (254mm) cement, mortar, and concrete specimens. It is an essential tool for laboratories and testing facilities conducting durability and performance evaluations of cementitious materials. Equipped with an Invar Reference Bar, the comparator ensures precise zeroing of the dial or digital indicator, offering consistent results every time.

Key Design Features:

• High Precision Measurement: Measures length changes in specimens with exceptional accuracy, making it ideal for testing shrinkage, expansion, and deformation of materials.
• Versatile Anvils: Stationary and movable anvils specifically designed to fit Gauge Studs cast into specimens, ensuring stable and reliable measurements.
• Multiple Specimen Sizes: While designed for specimens up to 4x4x10in (102x102x254mm) cross-sections, it can also accommodate 1x1x10in (25x25x254mm) prisms, commonly used for mortar bars.
• Features a 3.625in (92mm) diameter mechanical dial gauge marked from 0-10, with a measurement range of 0.4in (10mm) and gradations of .0001in (.003mm).

Robust Construction:

The Length Comparator is built for durability and reliability. It includes a sturdy vertical support stand mounted on a triangular base with an adjustable terminal and collar, ensuring stability during measurements. This robust design minimizes errors caused by vibrations or external factors.

What's Included:

• Length Comparator with your choice of Digital or Dial Indicator
• Invar Reference Bar for accurate zeroing
• Stationary and Movable Anvils for secure specimen positioning
• Solid Support Stand and Triangular Base for added stability
• Two lithium batteries for digital model operation
• Compact dimensions: 11 x 11.5 x 17in (279 x 292 x 432mm), WxDxH

Applications:

The Length Comparator is ideal for various test methods that assess the durability and behavior of cement, mortar, and concrete under different conditions. It is broadly used in research, quality control, and standards compliance.

Test Methods Supported:

• ASTM C227: Potential Alkali Reactivity of Cement-Aggregate Combinations (Mortar-Bar Method)
• ASTM C1260: Potential Alkali Reactivity of Aggregates (Accelerated Mortar-Bar Method)
• ASTM C1012/1012M: Resistance of Concrete to Sulfate Attack
• ASTM C151/151M: Autoclave Expansion of Hydraulic Cement
• ASTM C157/157M: Length Change of Hardened Hydraulic-Cement Mortar and Concrete
• ASTM C490/490M: Use of Apparatus for Length Change Measurements of Hardened Cement Paste, Mortar, and Concrete
• AASHTO R 70M/R 70: Determination of Length Change
• AASHTO T 107M/T 107: Determination of Autoclave Expansion

Additional Information:

The Length Comparator is an essential tool for laboratories conducting ASTM and AASHTO-compliant testing. Whether you're evaluating the sulfate resistance of concrete, monitoring the expansion of hydraulic cement, or assessing the potential reactivity of aggregates, this instrument delivers the precision and reliability you need.

Optional accessories, such as Gage Studs for Mortar Bars, are available separately and are required for use with cement prism molds.