Waveform observing apparatus

There is provided a waveform observing apparatus with a reduced depth in such a manner that the waveform observing apparatus is one including a terminal board, connecting wiring extending from external equipment, a memory for receiving measured data through the terminal board, to store the measured data, and a display for displaying the measured data in waveform, the apparatus including: a first intra-body substrate, installed in an erect state inside a body frame of the waveform observing apparatus; a plurality of first connectors, provided on the first intra-body substrate; and a measurement module, which is connector-connected to the first connector of the first intra-body substrate, to be installed between the first intra-body substrate and the terminal board, and also includes a measurement circuit, wherein a plurality of measurement modules are detachable in an aligned state with respect to the erect first intra-body substrate.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application claims foreign priority based on Japanese Patent Application No. 2008-199404, filed Aug. 1, 2008, the contents of which is incorporated herein by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a waveform observing apparatus.

2. Description of the Background Art

There has been used a waveform observing apparatus for observing a temperature and pressure of equipment on a factory production line. The apparatus historically used to be one for writing a waveform on rolled paper, but with the development of electronic equipment, a waveform observing apparatus that displays a waveform by use of a display in place of paper is currently in wide use.

The waveform observing apparatus is capable of displaying in a display section a constantly varying measured value, namely a time-series waveform, while storing measured data captured from a thermocouple or the like into a memory mounted to the waveform observing apparatus. For example, Japanese Patent Application Laid-Open No. H7-114349 and Japanese Patent Application Laid-Open No. 2002-82133 each disclose a waveform observing apparatus having a display with a touch panel. Japanese Patent Application Laid-Open No. H7-114349 proposes that, by an operator touching a function key displayed in a display section, a function designated by the function key displayed in the display section is executed. Japanese Patent Application Laid-Open No. 2002-82133 displays that, while a displayed waveform is observed, an operation of inputting a comment or a marking by pen-input is performed using a pen-input touch screen.

As for a conventional practical article of the waveform observing apparatus of this kind, a configuration has been adopted to have a solid metal-made frame and install a substrate incorporated with a measurement circuit, a computing circuit and the like in this metal frame. Further, in the conventional article, a terminal board corresponding to the number of channels requested by a user has been incorporated based upon this requested number of channels.

SUMMARY OF THE INVENTION

In general, the waveform observing apparatus is often used as being incorporated in a control board, and its height size and width size are typically defined to two kinds, for example. Therefore, with a certain degree of flexibility given to its depth size, the conventional practical article has not been sufficiently worked on in terms of reduction in depth size.

Further, since a technique of mounting terminal boards in accordance with the number of channels requested by the user has been adopted to the conventional practical article, there has been a problem in that, when the number of channels requested increases after the mounting, the user has a difficulty dealing with that increase.

An object of the present invention is to provide a waveform observing apparatus capable of reducing its depth size.

A further object of the present invention is to provide a waveform observing apparatus capable of immediately dealing with a subsequent variation in number of channels made by a user, having acquired the waveform observing apparatus, after the acquirement of the apparatus.

According to the present invention, the above technical problems are solved by providing a waveform observing apparatus, including

a terminal board, connecting wiring extending from external equipment,

a memory for receiving measured data through the terminal board, to store the measured data, and

a display for displaying the measured data in waveform,

the apparatus including:

a first intra-body substrate, installed in an erect state inside a body frame of the waveform observing apparatus;

a plurality of first connectors, provided on the first intra-body substrate; and

a measurement module, which is connector-connected to the first connector of the first intra-body substrate, to be installed between the first intra-body substrate and the terminal board, and also includes a measurement circuit,

wherein a plurality of measurement modules are detachable in an aligned state with respect to the erect first intra-body substrate.

Namely, according to the present invention, a first intra-body substrate that connector-connects a measurement module is arranged in an erect state, thereby allowing reduction in depth size of the waveform observing apparatus as compared with a case where this is arranged in the horizontal direction. Further, since preparing a plurality of first connectors on the intra-body substrate in the erect state can connect an arbitrary number of measurement modules, when the number of channels requested by the user increases or decreases, it is possible to deal with this by increasing or decreasing the number of measurement modules in accordance with the increase or decrease in the requested number.

In a preferred embodiment of the present invention, the measurement module and the terminal board are mutually connector-connected to constitute a measurement unit, and the terminal board is detachably fixed to walls of the body frame. With such a configuration adopted, a load of the terminal board connected with a large number of wiring can be applied on the body frame, and it is thus possible to suppress action of the load of the terminal board on the intra-body substrate in the erect state.

According to the preferred embodiment of the present invention, the measurement module houses two intra-module substrates vertically separately disposed inside a module case of the measurement module,

out of the two intra-module substrates, one intra-module substrate is installed with a second connector connector-connectable to the intra-body substrate, and the other intra-module substrate is installed with a third connector connector-connectable to the terminal board, and

out of the two intra-module substrates, either one is freely movably supported within a predetermined and fixed range with respect to the module case.

According to this embodiment, out of two intra-module substrates inside the measurement module, a floating support structure is adopted to one substrate, while second and third connectors on the terminal board side and the body side are mounted on the other intra-module substrate, and it is thereby possible to suppress transmission of the load from the terminal board to the body-side substrate.

Other objects and the action effects thereof become apparent from the following detailed descriptions of preferred embodiments of the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

In the following, a preferred embodiment of the present invention is described with reference to attached drawings.FIG. 1is a front view of a waveform observing apparatus1of an embodiment. The waveform observing apparatus1has a top-open waterproof cover3with a lower hinge below a display section2, and the waterproof cover3can be opened with a lower hinge5at the center by releasing a slide lock4.FIG. 2shows a state where the waterproof cover3is open. As seen from thisFIG. 2, opening the waterproof cover3can expose a main power switch6, a start/stop switch button7, a setting menu button8, a user setting key button9, a touch panel function lock switch button10, and a USB connector11.

The start/stop switch button7can be operated by the user, to start and stop collection of measured data. The setting menu button8can be operated by the user, to display a setting menu and display predetermined setting items from the setting menu. The user setting key button9can be arbitrarily allocated by the user, and the user setting key button9can be operated, to execute a function allocated by the user. As described later, the waveform observing apparatus1of the embodiment has a touch panel (numeral222inFIG. 3), and the touch panel function lock switch button10can stop the function of this touch panel222, to cancel out an input made by means of the touch panel222.

FIG. 3is an exploded perspective view of the waveform observing apparatus1, andFIG. 4is a block diagram of the same. The waveform observing apparatus1includes a body20and a detachable front unit22on the front surface of the body20. The front unit22is made up of a cosmetic panel220, a front surface frame221, a touch panel222, and a liquid display224having a back light223(FIG. 4). The touch panel222and the liquid display224with the back light constitute the display section2, and a waveform chart is displayed in the display section2as shown in the figure. Needless to say, the liquid display224is an example of the slim-type display.

A waterproof and protective sheet is provided as stretched over the cosmetic panel220, and with this waterproof and protective sheet provided as stretched over the cosmetic panel220, the terminal of the waterproof and protective sheet can be hidden by the front unit22, so as to improve the appearance of the waveform observing apparatus1.

The apparatus body20has a relay substrate201located in an erect state on its front surface, and a main substrate202that is connector-connected to the upper end of the relay substrate201and extends in the horizontal direction. The relay substrate201serves to supply a digitalized measurement signal to the main substrate202mounted with a CPU29as a control device, and is installed with ten measurement-unit connectors203and a total of four alarm-or-IO-unit connectors204. The relay substrate201and the main substrate202are housed inside a body frame205, as detailed later.

The relay substrate201constituting a first intra-body substrate is also installed with a power switch16and USB connector11. The main power switch6and the USB connector11are connected to the main substrate202constituting a second intra-body substrate, through the relay substrate201(FIG. 4). Namely, a configuration has been adopted in which, when the front unit22is removed from the apparatus body20, the main power switch6and the USB connector11can be left in the body20regardless of the removal of the front unit22. Thereby, for example in removal of the front unit22from the body20for replacement of the back light223, the main power switch6can be kept in an ON state. Therefore, while measured data continue to be collected in the waveform observing apparatus1, an operation to replace an element incorporated in the front unit22, typically, the replacement of the back light223or the liquid display224, can be performed. In other words, elements restricted to two functions, a display function and an input function (touch panel222), are incorporated in the front unit22, and hence the measured data collecting function of the waveform observing apparatus1can be continued even when the front unit22is removed from the body20.

With reference toFIG. 3, as detailed later, the box-shaped-body frame205having a rectangular cross-section and an open front and rear surfaces is made up of a metal-made outer frame206as an outer covering and an inner plastic frame207as a main constituent, thereby reducing the weight of the body frame205. In the plastic frame207, multistage shelves in two right and left columns for housing measurement units23and alarm or IO units24are formed (FIG. 5). It goes without saying that the configuration of the two right and left columns shown in the figure is a mere example, and the configuration may be formed of three right and left columns, or one column.

In the body frame205included in the embodiment, the measurement units23that are housed on the shelves except for the top two stages of shelves and the alarm or IO units24that are housed on the top two stages of shelves can be connector-connected by being inserted onto the shelves of the plastic frame207from its rear side. Namely, the relay substrate201that is located in the erect state ahead of the plastic frame207is installed with the connectors203,204in positions associated with the respective shelves of the plastic frame207, and the measurement units23and the alarm or IO units24can be connector-connected by being inserted onto the respective shelves of the plastic frame207.

The measurement unit23and the alarm or IO units24are respectively installed with terminal boards25on the rear surfaces thereof (FIG. 4), and the terminal board25of the measurement unit23is connected with wiring from a variety of sensors27such as a thermocouple, a resistance temperature sensor, a flow meter and a pressure sensor. Upon receipt of a signal from the sensor27, an intra-unit microcomputer28communicates with a CPU29of the main substrate202through the relay substrate201, and transmits measured data received from the sensor27to the main substrate202.

Namely, in the measurement unit23, a measurement signal from the sensor27is converted into a digital signal, and this digital signal is supplied to the main substrate202through the relay substrate201. The CPU29of the main substrate202serves to control the whole of the waveform observing apparatus1. The CPU29of the main substrate202performs signal processing in accordance with a predetermined program to store measured data into the body memory31in a predetermined cycle, and also generates an image signal for controlling drawing of the display section2. The main substrate202and the display section2are connected with each other through the relay substrate201. When the operator touches the touch panel222, a touched position signal or a coordinate signal, which corresponds to the touch, is supplied from the touch panel222to the CPU29of the main substrate202, and the CPU29realizes a function meant by a key corresponding to the touched place, or generates a signal for executing scroll of a waveform on display in the display section2based upon the coordinate signal.

The waveform observing apparatus1is installed into a control box32(FIG. 4) at the factory and can be connected to a personal computer34through an intra-factory LAN33. The personal computer34can display the same waveform as the waveform on display in the waveform observing apparatus1. Further, a copy of data stored in the body memory31of the waveform observing apparatus1can be retrieved by inserting the USB memory35as a removable recording medium into the USB connector11.

With reference toFIG. 5, as described above, the box-shaped body frame205of the apparatus body20is made up of the inner plastic frame207as the main constitute and the metal frame206as the outer covering, and the inner plastic frame207has an outer shape with an outline complementary to a rectangular outline of the metal frame206. The body frame205is assembled by inserting the inner plastic frame207into the metal frame206from its front surface side, whereby the body frame205has an outer/inner double frame structure formed of the plastic frame207as the main constitute and the metal frame206surrounding the outside of the plastic frame207as a structural main constitute.

When seen from its rear side, the inner plastic frame207has right and left vertical outer walls210, and a vertical central wall212that is located at the middle point between the outer walls210and vertically extends. Between the central wall212and the right and left outer walls210, insertion spaces214are respectively formed which extend in the longitudinal direction and longitudinally align the measurement units23and the alarm or IO units24. On the right and left outer walls210and the central wall212along the wall surfaces, which define the right and left insertion spaces214, a plurality of guiding projection216extending in the cross direction are integrally molded. These guiding projections216constitute substantial shelves that allow the measurement units23and the alarm or IO units24to be housed in a vertically aligned state in the right and left insertion spaces214. More specifically, in the right and left insertion spaces214, the modules230excluding the terminal boards25of the measurement units23and the alarm or IO units24are housed.

As described above, needless to add, the body frame205is not restricted to the module insertion spaces214in two right and left columns. For example, providing two vertical central walls212can form the insertion spaces214laterally in three columns. On the contrary, omitting the central wall212can form the single module insertion space214by the right and left vertical outer walls210.

As a modified example, the configuration of the vertical central wall212may be changed to a configuration extending in the lateral direction, to form the module insertion spaces214extending in the horizontal direction, so as to get the plurality of measurement units23and alarm or IO units24aligned in the lateral direction, namely aligned alongside.

FIG. 7is a cross-sectional view of the body frame205. As understood fromFIG. 7, the inner plastic frame207has a substantially symmetrical concavo-convex shape for forming the module insertion spaces214by the right and left outer walls210and the central wall212, and the right and left outer walls210and the central wall212have substantially the same widths and thicknesses. Namely, the inner plastic frame207are molded in concavo-convex shape, thereby forming the outer walls210and the central wall212both having widths and the right and left module insertion spaces214, and on the right and left outer walls210and the central wall212, rib-shaped guiding projections216are integrally molded in the shifting direction of the measurement unit23, namely in the cross direction and the horizontal direction. As thus described, with the inner plastic frame207integrally molded three-dimensionally in concavo-convex shape, it is possible to ensure structural rigidity. Further, it can be said that a plurality of guiding projections216that extend in the horizontal direction and serve to guide the measurement units23also contribute to ensuring the rigidity of the inner plastic frame207.

Reference numeral218shown inFIG. 7denotes positioning holes for the measurement unit23and the alarm or IO unit24. A pair of positioning holes218are provided right and left with a space therebetween with respect to each unit23(24) in the deep portion of the module insertion space214. One positioning hole218A is made up of small holes, and the other positioning hole218B is made up of a long hole extending in the lateral direction.

FIG. 8is a perspective view where the foregoing relay substrate201positioned in the vertically erect state and the main substrate202positioned in the state of being the connector-connected to the upper end of the relay substrate201and extending backward in the horizontal direction have been extracted. This perspective view is a view obliquely seen from the rear. The relay substrate201is installed on the front surface portion of the body frame205, and the main substrate202is installed on the upper end of the body frame205. With the relay substrate201positioned in the vertically erect state, the depth size of the waveform observing apparatus1can be made smaller than the conventional one. For the reference's sake, the depth size of the waveform observing apparatus1of the embodiment is about two-thirds of that of the conventional apparatus. Further, installing the main substrate202above an arranged position of the measurement unit23, preferably at the upper end of the body frame205, can reduce an influence on the measurement unit23exerted due to heat generated by the main substrate202.

FIG. 9is a perspective view of the vertically flipped measurement unit23, namely, a view of the measurement unit23seen from the bottom, andFIG. 10is a plan view of the same. The alarm or IO unit24has substantially the same appearance. The measurement unit23is made of the measurement module230and the terminal board25. The measurement module230and the terminal board26are connector-connected to each other, and thereby the terminal board26is detachable with respect to the measurement module230.

The measurement module230includes: a module body232having a width size W and a depth size (FIG. 10) which are substantially the same as those of the module insertion space214of the apparatus body20(FIGS. 6 and 7); a ventilation section233having a small width and extending backward from the rear end of the module body232; and right and left positioning pins235extending forward from the front end surface of the module body232. The ventilation section233is installed at the central portion in the width direction of the module body232.

When the measurement unit23is inserted into the module insertion space214, the positioning pin235gets into the foregoing positioning hole218(FIG. 7), thereby positioning the measurement unit23.

The module body232with the width W substantially the same as the width of the module insertion space214of the apparatus body20has a pair of right and left horizontal ribs236that project outward in the width direction from the rear end on both side surfaces of the module body232, and the front end of the horizontal rib236is made up of a taper surface236a(FIG. 10). This horizontal rib236has a function of inserting the measurement unit23into the module insertion space214and also guiding the move of the measurement unit23upon removing the measurement unit23from the module insertion space214by being friction-bonded to the upper surface of the guiding projection216of the inner plastic frame207, and also has a function of getting the measurement unit23, inserted into the module insertion space214, latched to the guiding projection216.

FIG. 11is an exploded perspective view of the measurement module230. The measurement module230has a lower case50and an upper case52which are vertically separable from each other. In an inner space formed by this lower and upper cases50,52, a lower substrate54and an upper substrate56separate from the lower substrate54are housed. These vertically separated substrates54,56are both made of a metal material excellent in thermal conductivity. The lower substrate54is mounted with a body-side connector section55at its front end edge, and this lower substrate54is connector-connected to the apparatus body20. Meanwhile, the upper substrate56is connected with a terminal board-side connector57at its rear end, and this upper substrate56is connector-connected to the terminal board25.

As described above, the measurement module230has the ventilation section233(FIG. 10) with a width and height sizes relatively smaller than those of the module body232. This ventilation section233has, in corresponding portions of the lower and upper cases50and52, a plurality of vertically penetrating first ventilation openings58and second ventilation openings60penetrating in the lateral direction. The first ventilation openings58are arranged as vertically aligned with respect to the lower and upper cases50,52. Namely, the measurement module230is ventilated in four directions, the upward and downward directions and the directions to the right and left, in the ventilation section233through the plurality of first ventilation openings58which are formed in the lower and upper cases50,52and aligned in a plan view, and the plurality of right and left second ventilation openings60.

As a preferred mode, the thermal conductive upper substrate56has a plurality of third ventilation openings62in a portion corresponding to the ventilation section233of the measurement module230, and the third ventilation openings62are aligned with the first ventilation openings58of the foregoing lower and upper cases50,52in a plan view.

With reference toFIG. 11, a fitting structure of the two vertically separated substrates54,56is described. The lower substrate54and the upper substrate56are connected with each other by a connector66mounted on one side of the lower substrate54and the upper substrate56. It is to be noted that, although only the connector66on the lower substrate54side is shown in relation to drawing of this figure, another connector engaged with the lower-substrate-side connector66is mounted on the upper substrate56.

In the lower case50, mounts68are formed in its four corners, and four corners of the lower hinge54are seated on these four mounts68. Further, in the lower case50, respective first bosses70are formed adjacently to the mounts68in the four corners, and in association with this, notch sections54aare formed in four corners of the lower substrate54. The notch section54ais located adjacently to the first boss70, so as to position the lower substrate54while allowing upward and downward, right and left movements of the lower substrate54to a certain degree.

Meanwhile, the upper case52is provided with respective second bosses72in two corners of its front end. This second boss72has a diameter larger than that of the first notch section54aof the lower substrate54. The second boss72is engaged with a periphery of the lower substrate54from the top, thereby to restrict lifting of the front portion of the lower substrate54. Further, the upper case52is provided with a pair of right and left projections74at its rear end, which are separated right and left and extend downward. The lower end of the projection74is located adjacently to the lower substrate54, so as to restrict lifting of the rear portion of the lower substrate54. It is to be noted that the body-side connector section55is provided at the front end edge of the lower substrate54, as described above.

Meanwhile, the upper substrate56is provided with second notch sections56ain two corners of its front end. The second boss72of the upper case52is inserted with clearance into this second notch section56a, and thereby the front end of the upper substrate56is positioned freely movably right and left and forward and backward in a fixed range. Further, at the rear end of the upper substrate56, third notch sections56bare formed which take the restricting projections74for controlling lifting of the lower substrate. This third notch section56bis larger than the restricting projection74, and thereby, the rear end of the upper substrate56is positioned freely movably right and left and forward and backward in a fixed range. It should to be noted that the upper case52is provided with a projection (not shown) for controlling excess lifting of the upper substrate56while allowing the lifting in a fixed range.

With the above configuration, the lower substrate54provided with the body-side connector section55and the upper substrate56provided with the terminal board-side connector section57are both supported as floated inside the lower and upper cases50,52, and further, relative displacement of the lower substrate54and the upper substrate56is allowed in a fixed range.

FIG. 12is a perspective view of the terminal board25seen from the measurement module230side, andFIG. 13is an exploded perspective view of the same. With reference toFIG. 13, the terminal board25has a terminal board base80, a terminal board body82, and a terminal board cover84. The terminal board25has the terminal table cover84between the terminal board base80and the terminal board body82, and a substrate86is housed between the terminal table base80and the terminal table body82. The substrate86extending along the terminal board body82is provided with a connector section88(FIG. 12). The terminal board25is connector-connected to the measurement module230by engagement of its connector section88with the terminal board-side connector section57of the measurement module230, to form the measurement unit23(FIGS. 9 and 10).

FIG. 14shows a state where the measurement unit23has been mounted in the apparatus body20, andFIG. 15shows a state where the terminal board25has been removed from the measurement unit23in the apparatus body20as inFIG. 14. As most obvious fromFIGS. 9 and 10described above, the terminal board25is designed to have a longitudinal size larger in the direction of the width W than that of the measurement module230, project right and left from the measurement module230, and has right and left ends seated on the right and left outer walls210of the rear surface of the body frame205(inner plastic frame207) and the central wall212of the body frame205.

Namely, the terminal board base80has, at its both longitudinal ends, a pair of legs90extending toward the apparatus body20side, and the end surfaces of the legs90can be seated on the right or left outer wall210and the central wall212of the body frame205.

As most apparent fromFIGS. 9 and 10, the pair of right and left legs90of the terminal board base80are located separately from the ventilation section233of the measurement module230, thereby forming an opening space S for heat generation extending upward and downward between each of the right and left legs90and the ventilation section233.

With reference toFIG. 13, the terminal board base80is fixed to the body frame205by a pair of first bolts92to be inserted into the legs90, and also the terminal board body82is detachably joined to the terminal board base80by use of the first bolts92. Meanwhile, the terminal board cover84is detachably joined to the terminal board body82by use of second bolts94.

For example in temperature measurement, the waveform observing apparatus1regularly performs a test on an input section for a measurement signal for keeping the accuracy of an input signal, namely a detected temperature. Since the measurement unit23included in the embodiment is detachable with respect to the apparatus body20and the terminal board25is detachable with respect to the measurement module230, by removing the measurement module230to be tested from the apparatus body, installing the terminal board25in the measurement module230for replacement which was previously prepared, and also installing the replacement terminal board25in the apparatus body20, it is possible to immediately resume measurement by use of this replacement measurement module230. In other words, while the state of wiring connection between the terminal board25and the external equipment is held, the measurement module230needed testing can be removed simply by replacement of only the measurement module230with the replacement measurement module230. The measurement module230needed testing may be subjected totesting and temperature calibration in an actual place, or may be sent to an agency provided with dedicated equipment.

With reference toFIG. 13again, a temperature sensor unit96can be built into the terminal board25. In other words, the temperature sensor unit96can be detachably mounted on the terminal board25.FIG. 16is an exploded perspective view of the temperature sensor unit96.

With reference toFIG. 16, in the temperature sensor unit96, a case104is made up of a box-shaped base member100having an erect wall98and an upper lid102that is fixed to the base member100, and a substrate106is housed inside the case104. The substrate106has a connector108, and is connected to the substrate86(FIG. 13) of the terminal board25by use of this connector108.

The substrate106of the temperature sensor unit96has a substrate extended section106aextending along the erect wall98of the base member100(FIG. 16). The upper end of the substrate extended section106aextends outward from the case104, and a temperature sensor IC110is installed on the upper end of this substrate extended section106a. This temperature sensor IC110gets into the inner space of the terminal board25surrounded by the terminal board base80and the terminal board body82for housing the substrate86along with the erect wall98, whereby an atmosphere temperature of the substrate housing space of the terminal board25is detected by use of the temperature sensor IC110.

As most apparent fromFIG. 13, the temperature sensor unit96is preferably installed in a position adjacent to the one leg90and also bordering the open space S with the measurement module230. AlthoughFIG. 12shows the terminal board25in a state where the user setting key button9is not mounted thereon, a portion where the user setting key button9is to be denoted by reference numeral112.

Since the temperature sensor unit96is detachable with respect to the terminal board25and the temperature sensor unit96can be removed by access from the outside, in order to check or test the accuracy of the temperature sensor unit96, removing the temperature sensor unit96to be tested from the terminal board25and mounting the temperature sensor unit96for replacement on the terminal board25allows immediate continuation of measurement.

According to the waveform observing apparatus1of the embodiment, since the body frame205is made up of the inner plastic frame207as the main constituent and is formed by a three-dimensional special structure having the right and left outer walls210and the central wall212of the inner plastic frame207, it is possible to ensure the rigidity while reducing the weight of the waveform observing apparatus1as compared with the conventional case where the body frame205is singly made of metal. Further, the rib-shaped guiding projections216integrally molded on the outer walls210and the central wall212can also enhance the rigidity of the inner plastic frame207. Moreover, fixing both the right and left ends of the terminal board25, extending over the outer walls210and the central wall212, to the outer walls210and the central wall212allows the terminal board25to further enhance the rigidity of the body frame205.

According to the waveform observing apparatus1of the embodiment, since the measurement unit23can be detached with respect to the apparatus body20in a cassette system, a user having acquired the waveform observing apparatus1can additionally provide or remove the measurement unit23in the case of an increase/decrease in the number of channels depending upon circumstances after the acquirement, so as to adjust the number of channels to an arbitrary number.

Further, with the measurement unit23and the relay substrate201installed in the erect state, the depth size of the waveform observing apparatus1can be reduced as compared with the conventional depth. Moreover, with the main substrate202installed backward from the upper end of the relay substrate201in the horizontal direction, a thermal influence of the measurement unit23exerted due to a heat generated by the main substrate202can be suppressed.

Further, the measurement unit23in a one-side held state which is connector-connected to the erect relay substrate201and extends in the horizontal direction is added with a weight of wiring with the external equipment wiring-connected to the terminal board25at its rear end. Since the terminal board25constituting part of the measurement unit23is fixed to the central wall212and either the right or left outer wall210of the body frame205(inner plastic frame207), it is possible to improve the supporting rigidity of the terminal board25. In other word, since a weight load of the rear end of the terminal board25can be applied on the body frame205, it is possible to stabilize inputting/outputting of the waveform observing apparatus1that is used for a long period of time by the year.

Further, the measurement unit23is made up of the measurement module230and the terminal board25having a different structure from the measurement module230. The substrate of the measurement module230is made up of the two substrates, the lower substrate54and the upper substrate56. Meanwhile, the one substrate (lower substrate)54is provided with the body-side connector section55, and the other substrate (upper substrate)56is provided with the terminal board-side connector section57, and the floating support structure is adopted in which relative displacement of the other substrate56with respect to the one substrate54is allowed in a fixed range. Accordingly, this floating support structure can prevent external force applied to the terminal board25from reaching the relay substrate201of the apparatus body20, and also seek for thermal insulation between the terminal board25and the apparatus body20with its configuration in which one of the vertically separated substrates54,56is connected to the terminal board25and the other is connected to the apparatus body20.

Further, not only the measurement unit23is made detachable with respect to the apparatus body20, but the terminal board25constituting part of this measurement unit23is made detachable with respect to the measurement module230. Hence, for the purpose of accurate testing on the measurement module230, the measurement module230can be replaced by the replacement measurement module230so that only the module body232can be removed. Thereby, a measurement operation suspending period of the waveform observing apparatus1for periodic checkup of the module body232can be held short. It goes without saying that, during the replacement of the module body232, there is no need for releasing the wiring connection between the terminal board25and the external equipment.

Further, with the ventilation section233provided between the module body232of the measurement module230and the terminal board25, the terminal board25and the module body232can be thermally insulated from each other, and also heat inside the measurement module230can be discharged to the outside. Moreover, since the upper and lower first ventilation openings58constituting this ventilation section233are aligned in a plan view, an upward gas flow can be made by the first ventilation openings58, so as to improve thermal dissipation efficiency. Furthermore, since the third ventilation openings62aligned with the first ventilation openings58in a plan view are provided on the substrate (upper substrate)56that receives an input from the terminal board25, the upper substrate56can be air-cooled by the above-mentioned upward gas flow, leading to further efficient thermally insulation from the terminal board25. Additionally, since the lower and upper substrates54,56installed inside the measurement module230are both configured of a substrate made of a metal material excellent in thermal conductivity, it is possible to make thermal dispersion and thermal distributions of the substrates54,56further uniform.

Further, since the second ventilation openings60are provided on the right and left side walls of the ventilation section233, and also the opening space S vertically extending to the right and left of this ventilation section233is formed, it is possible to enhance efficiency of thermal dispersion and air cooling of the terminal board25and the measurement module230.

Further, taking the foregoing measure against heat can prevent exertion of an adverse effect on the measured data due to the heat of the terminal board25. Especially when the objects to be measured by the waveform observing apparatus1includes temperature measurement, an error in measured data due to the heat of the terminal board25needs to be corrected, but since the heat of the terminal board25can be dispersed by the forgoing measure against heat, not only a value to be corrected due to the heat of the terminal board25can be made smaller, but also the thermal distribution of the substrate housing space of the terminal board25can be made uniform so as to improve the accuracy in temperature detection by the temperature sensor unit96. Moreover, since the temperature sensor unit96is provided in a position bordering the opening space S to the side of the ventilation section233so as to detect an atmosphere temperature of the substrate housing space of the terminal board25by this temperature sensor unit96, it is possible to further improve the accuracy in detecting an internal temperature of the terminal board25.

Further, since the temperature sensor unit96can be easily removed by access from the outside, it is possible to readily remove the temperature sensor unit96at the time of performing a test on the detection accuracy of the temperature sensor unit96, and also immediately mount the previously prepared replacement temperature sensor unit96on the terminal board25.