Internal micrometers, as well as external micrometers, find application in precision measurement.
But bore measurement is more difficult than external measurement of components. Apart from the compliance with the very tight tolerances specified for an application, all measuring elements having a direct influence on the uncertainty of measurement must be designed in such a way that they can fit into the bore to be checked.
The great advantage of TESA 3-line contact micrometers is the self-centering and self-alignment provided by the instruments, which allow to measure bores in a simple, reliable and intuitive way regardless of the operator's adjustments. The instrument is in fact positioned correctly inside the bore thanks to the three measuring bolts spaced at intervals of 120°, which guarantee an optimal self-centering, thus reducing the possibility of wrong measurements. Furthermore, the linear contact of the 3 bolts allows the perpendicular self-alignment of the instrument with respect to the enveloping surface.
The 3-line contact internal micrometers also detect form errors (for example, run-out errors) by taking measurements in different points within a bore.
While plug gauges, having a fixed dimension, can check only one toleranced size, all internal micrometers have a variable measuring range and are therefore suitable to measure many diameters. A single tool can thus replace several plug gauges.
The IMICRO® an internal micrometer unique of its kind, with an extraordinary longevity, whose mechanical principle is close to perfection. Invented in 1950, it has often been copied, but never equaled. The grinded hard metal threaded measuring cone, which represents the heart of the measuring head, and the specially arranged 3 contacts make IMICRO® the only internal micrometers in the world that respect the Abbe principle. Among the other unique features of this patented micrometer, which is still unmatched, we have to mention:
- the constant measuring force, with a clutch system with a ratchet integrated in the rapid drive;
- the absence of influence of the temperature on measurements, thanks to its construction that limits the expansion over the length;
- the unbeatable wear protection thanks to the titanium nitride hard-coating of the measuring faces;
- the possibility to mount extensions up to 1000 mm between the measuring head and the reading unit, guaranteeing optimal measurements even at great depths.
Available in more than 100 different models to cover diameters from 3,5 to 300 mm, it has been produced for over 20 years also in digital version, with the TESA patented capacitive measuring system CAPA µ SYSTEM®.
Furthermore, an adapter allows to apply the electronic measuring element of an IMICRO® CAPA µ SYSTEM® on the measuring head of an old generation digital IMICRO® or of an analogue IMICRO®, which can thus be updated to a recent electronic version, compatible with the TESA TLC-BLE Bluetooth® connectivity system, for the wireless data transmission.
Available individually or in sets in practical cases, complete with setting rings and extensions, these micrometers stand out for their robust construction, which guarantees longevity and stability of results over time, and for the quality of their materials.
The range also includes several accessories for depth measurements, with extensions up to 1000 mm and centering devices, as well as setting rings from 4 to 275 mm diameter.