ID numbers of connected multiple modules are easily automatically set.

Each of the multiple modules includes an ID number information holding unit that holds its own ID number information, a first command generation unit that generates a first command for notifying its rear stage of its own ID number information, a first command output unit that outputs the first command from a rear-stage output port, a second command generation unit that generates a second command for notifying its front stage of its own ID number information and ID number information on its rear-stage modules, a second command output unit that outputs the second command from a front-stage output port, and an ID number information update unit that sets, when the first command is received from a front-stage module, new ID number obtained by adding “1” to the ID number of the front-stage module contained in the received first command as its own ID number information in the ID number information holding unit. Each of the multiple modules outputs the first command and second commands for a predetermined period of time to assign a different ID number to each of the multiple modules connected to a network apparatus.

A roundness measuring device includes an annular ring, and a plurality of displacement sensors (comparative length measuring devices) provided on the ring at predetermined intervals. The displacement sensors are arranged such that lines along which measurement axes of the displacement sensors extend intersect at a single point.

A roundness measuring device includes an annular ring, and a plurality of displacement sensors (comparative length measuring devices) provided on the ring at predetermined intervals. The displacement sensors are arranged such that lines along which measurement axes of the displacement sensors extend intersect at a single point.

Provided is a micro head having a simple structure and yet entailing extremely little backlash.

A micro head includes a spindle, a sleeve, a thimble, a backlash absorbing member, and a collar, wherein the cylindrical backlash absorbing member is fixed to the sleeve in a state where the spindle is inserted at a position in the sleeve.

There is provided a digital micrometer suitable for measuring an object to be measured that is a strong magnet.

A digital micrometer includes a main-body frame, a spindle, a thimble part, and a displacement detector that detects displacement of the spindle. The main-body frame includes an U-shaped frame part, and a spindle holding part provided on the other end side of the U-shaped frame part and having a length in a direction away from an anvil. The spindle is held by a spindle holding part, provided to be movable forward and backward in an axial direction with respect to the anvil, and includes a contactor on one end face. The main-body frame and the spindle are formed of a non-magnetic material.

There is provided a digital micrometer suitable for measuring an object to be measured that is a strong magnet.

A digital micrometer includes a main-body frame, a spindle, a thimble part, and a displacement detector that detects displacement of the spindle. The main-body frame includes an U-shaped frame part, and a spindle holding part provided on the other end side of the U-shaped frame part and having a length in a direction away from an anvil. The spindle is held by a spindle holding part, provided to be movable forward and backward in an axial direction with respect to the anvil, and includes a contactor on one end face. The main-body frame and the spindle are formed of a non-magnetic material.

There is provided a method for controlling a small-sized adjustable measuring force measurement device capable of appropriately setting the origin. A central control unit changes an operation mode to an origin setting mode in response to predetermined mode changing operation. The central control unit sets a counter value of an encoder to zero as an origin when a measuring force detecting means detects that a movable member is brought into contact with an object to be measured at a predetermined pressure in the origin setting mode.

There is provided a method for controlling a small-sized adjustable measuring force measurement device capable of appropriately setting the origin. A central control unit changes an operation mode to an origin setting mode in response to predetermined mode changing operation. The central control unit sets a counter value of an encoder to zero as an origin when a measuring force detecting means detects that a movable member is brought into contact with an object to be measured at a predetermined pressure in the origin setting mode.

A system for measuring a changing crack, comprises: a measurement device comprising a body bearing a measurement instrument and having a first positioning means, and a movable member comprising a second positioning means; at least two targets that are able to cooperate with a positioning means, wherein the at least two targets are hemispherical in shape and wherein the positioning means consist of rings having a cross section that is smaller than the base section of the target.

A system for measuring a changing crack, comprises: a measurement device comprising a body bearing a measurement instrument and having a first positioning means, and a movable member comprising a second positioning means; at least two targets that are able to cooperate with a positioning means, wherein the at least two targets are hemispherical in shape and wherein the positioning means consist of rings having a cross section that is smaller than the base section of the target.