This instrument makes accurate measurements of the indentations for all Brinell type hardness testers. Our Brinell Microscope RBM-55 is a compact, yet durable instrument, making it suitable for both the shop and laboratory. The reticle is calibrated in 0.01 mm. Units over a range of 6mm. and the field of view is 7mm. Measure the indentation at its largest diameter against the reticle scale.