JP2013221760A - Measuring device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable checking a determination result to a measurement value while a sight line is turned to a test lead.SOLUTION: A measuring device includes: a test lead 2; a measuring portion ME connected to the test lead 2 through a cable 4, and measuring an insulation resistance value R about a measuring object such as an electric wire contacting with the test lead 2; a light-emitting diode 14 arranged on the test lead 2; and a processing portion 34 for comparing the insulation resistance value R measured by the measuring portion ME with a reference resistance value regulated in advance, and displaying the comparison result by the light-emitting diode 14.

Description

  The present invention relates to a measuring apparatus that measures a physical quantity of a measuring object by bringing a test lead into contact with the measuring object.

  As this type of measurement apparatus, a measurement apparatus (insulation resistance meter) for measuring insulation resistance disclosed in Non-Patent Document 1 below is known. This measuring device includes a main body and a pair of (red and black) test leads. By contacting the test leads with a pair of wires, the insulation resistance between the wires is measured as a physical quantity by using the pair of wires as a measurement object. Measure as

  In this measuring apparatus, first, the black test lead is connected to the ground-side wire of the pair of wires, and the red test lead is brought into contact with the remaining wires. Next, a measurement start switch (measure switch) of the measuring device is pressed. Thus, the measuring device measures the insulation resistance between the pair of test leads, that is, between the pair of electric wires, and displays the measured insulation resistance on the display (LCD) of the main body.

  This measuring device also has a comparator function (insulation resistance comparison / determination function), and compares the reference value defined in advance with the measured resistance value of the insulation resistance (also called a measured value) to determine the measured value. The determination result is output to the display unit of the main body. In this measuring apparatus, as an example, when the measured value is less than the reference value, the characters “Lo” are displayed on the display and the buzzer provided in the main body is sounded. On the other hand, when the measured value is greater than the reference value, , “Hi” is displayed on the display, and the buzzer does not sound. Thereby, it is possible to confirm the quality (determination result) of the measured insulation resistance.

3453, 3453-01 Digital Megohm HiTester (Insulation Resistance Tester) Instruction Manual, Revised January 2012, 14th Edition, Hioki Electric Co., Ltd. website [Search on March 22, 2012], Internet <http: // hioki .jp / manual / field-c / 3453A980-14.pdf>

  However, the above measuring apparatus has the following problems to be improved. That is, in this measuring apparatus, the determination result obtained by comparing the measured value with the reference value is displayed on the main body. In general, the operator's line of sight when measuring the physical quantity of the measurement object is mainly directed to the tip side of the test lead that is in contact with the measurement object. It is necessary to move from the side to the main body side. For this reason, it is preferable that the determination result can be confirmed with the line of sight directed toward the test lead. In addition, since the measuring device has a function of notifying the determination result based on the presence or absence of the buzzer, the measurement device confirms the determination result based on the presence or absence of the buzzer while keeping the line of sight toward the test lead. However, since it may be difficult to confirm the presence or absence of a buzzer in a noisy environment, it is preferable that the determination result can be confirmed visually.

  The present invention has been made in order to improve such a problem, and has as its main object to provide a measuring apparatus that can confirm a determination result for a measured value while keeping a line of sight toward a test lead.

  In order to achieve the above object, the measuring apparatus according to claim 1 is a measuring unit that is connected to the test lead via a test lead and a cable and measures a physical quantity of a measurement object that is in contact with the test lead. A display unit disposed on the test lead, and a processing unit that compares the physical quantity measured by the measurement unit with a predetermined reference physical quantity and displays the comparison result on the display unit. I have.

  The measuring device according to claim 2 is the measuring device according to claim 1, wherein the test lead extends along a length direction of the grip portion from a columnar grip portion and one end side of the grip portion. The grip portion is formed with an inclined surface in a direction opposite to the extending direction of the contact electrode portion, and the display portion is disposed on the inclined surface.

  The measuring device according to claim 3 is the measuring device according to claim 1 or 2, wherein a switch is disposed in the grip portion, and the processing portion is connected to the measuring portion when the switch is operated. On the other hand, the measurement of the physical quantity is started.

  According to the measuring apparatus of the first aspect, since the display unit is disposed on the test lead, the operator can check the display state of the display unit without diverting the line of sight from the test lead. The determination result about the state of the measurement object can be surely confirmed based on the displayed state. Therefore, according to this measuring apparatus, the time until the determination result is recognized as compared with the conventional measuring apparatus that needs to keep a gaze away from the test lead in order to confirm the determination result about the state of the measurement object. It can be greatly shortened.

  In addition, according to the measuring apparatus of the second aspect, the display unit is disposed on the slope formed on the grip portion of the test lead, so that the measurement object can be measured with one hand holding the test lead extended. Even in a situation where the test leads are in contact, that is, in a situation where the test leads can only be seen from the front side, the display state of the display unit (that is, the determination result regarding the state of the measurement object) can be reliably confirmed.

  In addition, according to the measuring apparatus of claim 3, since the switch can be operated without distracting the line of sight from the test lead by arranging the switch on the test lead, the measurement object and the test lead are in contact with each other. The physical quantity of the object to be measured can be measured while maintaining a good state. Therefore, according to this measuring apparatus, since the physical quantity of the measurement object can be measured accurately, the state of the measurement object can be accurately determined based on the measured physical quantity.

1 is an external view of an insulation resistance meter 1. FIG. 1 is a configuration diagram of an insulation resistance meter 1. FIG.

  Hereinafter, embodiments of a measuring apparatus will be described with reference to the accompanying drawings. In this example, as an example of a measurement apparatus, an insulation resistance meter 1 that measures the insulation resistance of a measurement object as a physical quantity will be described as an example.

  First, the configuration of the insulation resistance meter 1 will be described with reference to FIGS.

  As shown in FIGS. 1 and 2, the insulation resistance meter 1 includes, as an example, a pair of test leads 2 and 3, cables 4 and 5, and a main body 6, and as a physical quantity of a measurement object (for example, an electric wire). The insulation resistance value R can be measured.

  As shown in FIGS. 1 and 2, the test lead 2 includes a case 11, a contact electrode 12, a switch 13, and a light emitting diode 14 as a display unit, and is connected to the main body 6 through a cable 4. The case 11 includes, as an example, a columnar grip portion 21, and a lead portion 22 that extends along the length direction of the grip portion 21 from one end side (left end side in FIG. 1) of the grip portion 21, and includes an insulating material. (For example, a resin material having insulating properties). Note that the test lead 2 is shown exaggerated and larger than the test lead 3 and the main body 6 in order to facilitate understanding of the configuration.

  The contact electrode 12 is disposed at the tip of the lead portion 22. With this configuration, the contact electrode portion 23 composed of the contact electrode 12 and the lead portion 22 is disposed in the grip portion 21 in a state of extending from the one end side of the grip portion 21 along the length direction of the grip portion 21. Has been.

  The grip portion 21 is formed to a thickness that can be held with one hand throughout, and in this example, as an example, the one end side is the other end side (the right end side in FIG. 1) with the intermediate portion as a boundary. It is comprised in the shape thicker than this part. In addition, with this configuration, an intermediate portion of the grip portion 21 (a boundary portion between the one end portion and the other end portion) has an inclined surface (the grip portion 21 opposite to the extending direction of the contact electrode 12). ) 21a is formed to face the other end side of the region). As an example, the switch 13 is formed of a push button switch, and is disposed on the surface of one end side of the grip portion 21 configured as described above. The light emitting diode 14 is disposed on the inclined surface 21 a so as to be visible from the outside of the grip portion 21. Further, the light emitting diode 14 is configured to be lit in any one of red and green as an example by being controlled by the processing unit 34 (see FIG. 2).

  As an example, the test lead 3 is formed of a mouth clip made of a conductive material. The test lead 3 is connected to the main body 6 via the cable 5.

  As an example, the main body 6 includes a main body case 31, a voltage generation unit 32, a current measurement unit 33, a processing unit 34, and an output unit 35. The main body case 31 is formed in a rectangular parallelepiped as an example using an insulating material (for example, a resin material having an insulating property), and accommodates the voltage generation unit 32, the current measurement unit 33, and the processing unit 34. As shown in FIG. 1, an output unit 35 constituted by a display device is disposed on one surface (front surface) of the main body case 31 as will be described later.

  The voltage generation unit 32 constitutes a measurement unit ME together with the current measurement unit 33 and the processing unit 34, and is connected to the test lead 3 via the wiring in the cable 5. The voltage generation unit 32 is controlled by the processing unit 34 to generate a measurement voltage V having a known voltage value V1 based on a reference potential (internal ground of the main body 6) G in the main body case 31. And output to the test lead 3 via the cable 5.

  The current measuring unit 33 is disposed between the wiring in the cable 4 connected to the contact electrode 12 of the test lead 2 and the reference potential G. The current measuring unit 33 is connected to the test leads 2 and 3 and the measurement voltage V is applied to the measurement target body from the voltage generation unit 32 via the test leads 3. The current I flowing from the voltage generator 32 to the reference potential G via the cable 5, the test lead 3, the measurement object, the test lead 2, the cable 4, and the current measurement unit 33 (that is, the measurement object) Current value I1 of flowing current) is measured and output to the processing unit 34.

  For example, the processing unit 34 includes a CPU and a memory (both not shown), and executes control processing for other components (specifically, the voltage generation unit 32) and the output unit 35 of the measurement unit ME. . Further, the processing unit 34 is connected to the switch 13 of the test lead 2 through the wiring in the cable 4 and detects the operation state with respect to the switch 13 (in this example, whether or not the switch 13 is pressed). When the state in which the switch 13 is pressed is detected, resistance measurement processing and resistance determination processing are executed. Further, in this resistance measurement process, the processing unit 34 calculates (measures) the insulation resistance value R of the measurement object based on the voltage value V1 of the measurement voltage V and the current value I1 of the current I, and In this resistance determination process, the insulation state of the measurement object is determined based on the calculated insulation resistance value R.

  Further, the processing unit 34 is connected to the light emitting diode 14 via the wiring in the cable 4 and is configured to be able to perform lighting control on the light emitting diode 14. Further, the memory constituting the processing unit 34 has a reference resistance value (reference physical quantity) for determining in the resistance determination process whether the voltage value V1 of the measurement voltage V and the insulation resistance value R measured in the resistance measurement process are good or bad. Is stored in advance. The output unit 35 is configured by a display device such as an LCD (Liquid Crystal Display) as an example, and displays the value of the insulation resistance value R measured by the processing unit 34 constituting the measurement unit ME.

  Next, the measurement operation for the insulation resistance value R of the measurement object (electric wire) by the insulation resistance meter 1 will be described with reference to the drawings.

  First, the operator defines the ground potential by connecting the test lead 3 to, for example, a grounded earth bar. Next, the operator grasps the grip part 21 of the test lead 2 with one hand, brings the contact electrode 12 into contact with the measurement object, and presses the switch 13 in this state, thereby measuring the measurement object against the insulation resistance meter 1. Insulation resistance value R is measured, and determination (inspection) of the measured insulation resistance value R is executed. In this insulation resistance meter 1, since the switch 13 is disposed on the test lead 2, the operator can operate the switch 13 without deviating the line of sight from the test lead 2. It is possible to cause the insulation resistance meter 1 to start measuring the insulation resistance value R while maintaining a good contact state between the body and the test lead 2.

  In the insulation resistance meter 1, the processing unit 34 detects an operation on the switch 13 and executes resistance measurement processing. In this resistance measurement process, the processing unit 34 first functions as the measurement unit ME together with the voltage generation unit 32 and the current measurement unit 33, and the insulation resistance between the measurement object contacting the test lead 2 and the ground. The value R is measured. Specifically, the processing unit 34 first performs control on the voltage generation unit 32 to start generation of the measurement voltage V (that is, start application of the measurement voltage V to the measurement object). . Next, the processing unit 34 acquires the current value I1 of the current I flowing through the current path from the current measurement unit 33. Subsequently, the processing unit 34 calculates (measures) the insulation resistance value R of the measurement object based on the acquired current value I1 and the voltage value V1 of the measurement voltage V stored in the memory, and stores the memory. To remember. Finally, the processing unit 34 causes the output unit 35 to display the calculated insulation resistance value R. Thereby, the resistance measurement process is completed.

  Next, the processing unit 34 executes a resistance determination process. In this resistance determination process, the processing unit 34 reads and compares the measured insulation resistance value R stored in the memory and the reference resistance value stored in advance. As a result of this comparison, when the measured insulation resistance value R is greater than or equal to the reference resistance value, the processing unit 34 determines that the insulation state of the measurement object (the state of the measurement object) is good, and By executing the lighting control, the light emitting diode 14 is lit in green. On the other hand, as a result of this comparison, when the measured insulation resistance value R is less than the reference resistance value, the processing unit 34 determines that the insulation state of the measurement object is defective, and executes the lighting control for the light emitting diode 14. As a result, the light emitting diode 14 is lit in red. Thus, the resistance measurement process and the resistance determination process are completed.

  As described above, according to the insulation resistance meter 1, since the light emitting diode 14 is arranged on the test lead 2, the operator can turn on the light emitting diode 14 (display state) without diverting the line of sight from the test lead 2. In addition, the quality of the insulation state of the measurement object (determination result for the measurement value) can be reliably confirmed based on the confirmed lighting state. Therefore, according to this insulation resistance meter 1, it is recognized whether the insulation state is good or not as compared with the conventional measuring apparatus that requires the line of sight to be separated from the test lead 2 in order to confirm the determination result of the insulation state of the measurement object. The time to do this can be greatly reduced.

  Further, according to the insulation resistance meter 1, the slope 21 a formed on the grip portion 21 of the test lead 2, that is, the direction opposite to the extending direction of the contact electrode 12 (the portion on the other end side of the grip portion 21). The light emitting diode 14 is disposed on the inclined surface 21a facing the direction), so that the test lead 2 is in contact with the measurement object with one hand holding the test lead 2 extended, that is, the test lead 2 is in front. Even in a situation in which the light-emitting diode 14 can be visually recognized only from the side (the part on the other end side of the grip portion 21), the lighting state of the light-emitting diode 14 can be reliably confirmed.

  Further, according to the insulation resistance meter 1, since the switch 13 is disposed on the test lead 2, the switch 13 can be operated without diverting the line of sight from the test lead 2, so that the measurement object and the test lead 2 can be operated. It is possible to measure the insulation resistance value R of the measurement object while maintaining the contact state in a good state. Therefore, according to this insulation resistance meter 1, since the insulation resistance value R of the measurement object can be accurately measured, the quality of the insulation state of the measurement object can be accurately determined.

  In addition, although the insulation resistance meter 1 which is a measuring apparatus which measures and determines the insulation resistance value R as an example of the physical quantity as the measurement object has been described as an example, the voltage value or current as the physical quantity of the measurement object is described. The present invention can also be applied to a voltmeter or ammeter that is a measuring device that measures and determines a value, and a thermometer that is a measuring device that measures and determines a temperature as a physical quantity of a measurement object.

  Further, as an example of the light emitting diode 14, a light emitting diode having a configuration of lighting in two colors of green and red has been described as an example, but the lighting color can be defined as an arbitrary color. In addition, a configuration in which two light emitting diodes that are lit in one color are used to form the light emitting diode 14 (display unit) may be employed. In addition, a light-emitting diode that is lit in one color is used as the light-emitting diode 14 (display unit), and a comparison result between the measured physical quantity and the reference physical quantity is displayed depending on whether or not the light-emitting diode 14 is lit (display state). A configuration can also be adopted. Further, as an example of the display unit disposed on the test lead 2, a configuration using the light emitting diode 14 is adopted. However, a configuration using a lamp instead of the light emitting diode can be adopted, and an LCD or the like can be used. It is also possible to employ a configuration in which characters or symbols indicating good or bad are displayed using the display device.

  Further, in order to improve the visibility of the light emitting diode 14 from the front side (the other side of the grip portion 21), the slope 21a is formed on the grip portion 21, and the light emitting diode 14 is disposed there. However, when it is not necessary to improve the visibility of the light-emitting diode 14, a configuration in which the slope 21a is not formed on the grip portion 21 can be adopted. In this configuration, the light-emitting diode 14 is attached to the grip portion 21. It can be arranged at any position on the surface.

DESCRIPTION OF SYMBOLS 1 Insulation resistance meter 2,3 Test lead 13 Switch 14 Light emitting diode 32 Voltage generation part 33 Current measurement part 34 Processing part ME measurement part

Claims (3)

Test leads,
A measurement unit that is connected to the test lead via a cable and measures a physical quantity of a measurement object that is in contact with the test lead;
A display unit disposed on the test lead;
A measurement apparatus comprising: a processing unit that compares the physical quantity measured by the measurement unit with a predetermined reference physical quantity and displays the comparison result on the display unit. The test lead includes a columnar grip portion, and a contact electrode portion extending along the length direction of the grip portion from one end side of the grip portion,
The grip portion is formed with an inclined surface facing in a direction opposite to the extending direction of the contact electrode portion,
The measuring apparatus according to claim 1, wherein the display unit is disposed on the slope. A switch is disposed in the grip part,
The measurement apparatus according to claim 1, wherein the processing unit causes the measurement unit to start measuring the physical quantity when the switch is operated.

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