Dial Gauge, Flat Back, ISO Type

Mitutoyo 2900AB-70 – dial indicator, flat back, ISO type

The Mitutoyo 2900AB-70 is an accurate analogue dial indicator with a metric scale and a division accuracy of 0.001 mm. It is a single turn model, meaning that the entire measuring range is indicated with a single turn of the pointer. This eliminates the potential for error that can arise from counting multiple revolutions and makes interpretation of readings quick and reliable, for example in the machine shop or for quality control.

With a measuring range of 0.08 mm, a plunger travel length of 4 mm, and a measurement per revolution of 0.1 mm, the dial is implemented as a 40-0-40 scale, making it easy to monitor deviations from the central zero in both directions. The manufacturer's specified maximum permissible error over the entire measuring range is 3 µm and 2 µm over one tenth of a turn, with hysteresis at 2 µm and repeatability at 1 µm, making the gauge suitable for demanding precision measurements where measurement result repeatability is important.

The body has no through-bolt holes, and the O-ring seal prevents water and oil from penetrating the gauge, which improves reliability in industrial environments. The gauge is also shock-resistant and conforms to the EN ISO standard for dial indicators. The product is supplied with a manufacturer's inspection certificate, ensuring that its accuracy and performance are documented to meet the manufacturer's standards.

The dial indicator has an 8 mm stem and a carbide-tipped measuring tip with M2.5 × 0.45 mm thread. The measuring force is stated by the manufacturer to be 0.4–2 N, ensuring secure contact with the measured surface without excessive force. With a mass of approximately 141 grams, the gauge is robust enough for stable measurement, yet still light to handle and move. Optional green limit indicators are available, making it easy to monitor set tolerance limits directly from the dial.