Differential Micrometer Head, 13 mm Coarse, 0.2 mm Fine, 462 Stage Bracket

When manual resolution of much less than one micrometer is needed, a differential screw is recommended. A differential micrometer uses a spindle with two opposing screw threads of slightly differing pitches (P1 and P2). As the spindle rotates, the net travel of the micrometer tip is : 1/Peff = 1/P1 - 1/P2. This mechanism allows extremely small adjustments using commonly available screws.

The DM-13 combines 13 mm of coarse travel range with 0.2 mm fine adjustability in a single micrometer. Use the knob at the back for coarse positioning like a classical micrometer drive. When done, use the other knob for fine tuning your position with 0.07 µm adjustment sensitivity. The motion of the DM-13 is exceptionally smooth and crisp, without tightness or difficult turning. DM-13 provides excellent linearity and absolute accuracy better than 1%, and its unique design exhibits no harmonic motion errors typical of conventional differential screws.

The DM-13B is a DM-13 differential micrometer supplied with a mounting bracket specifically for use with our 462 Series stages. Note that the micrometer mounting bracket(s) supplied with the 462-series stages are sized for 1.0-in. (25 mm) travel. Therefore, the DM-13B includes a different micrometer mounting bracket which accounts for the shorter 0.5-in (13-mm) range, allowing symmetric travel about the 462’s nominal position.