JPH07225199A - Method and apparatus for detecting deterioration of insulated coated electric wire - Google Patents

Abstract

(57) [Summary] (Modified) [Purpose] To provide a method and device for detecting the deterioration of an insulation-coated electric wire that allows nondestructive measurement of the insulation-coated electric wire and easily and quantitatively determine the degree of deterioration of the insulation coating. provide. A measuring unit 2 is provided with an optical sensor 4 which uniformly irradiates a predetermined range in the longitudinal direction of the insulating coated electric wire 3 and measures the reflected light from the insulating coated surface in the longitudinal direction of the electric wire 3 as a light intensity distribution waveform. The main body 1 digitally converts the light intensity distribution waveform into a reflection intensity sequence that is a data sequence of brightness values A
/ D converter, a waveform storage device that stores a reflection intensity sequence, an arithmetic device that calculates the degree of deterioration of the insulating coating based on the reflection intensity sequence and a threshold value that is a predetermined crack determination reference value, and a deterioration degree And an output device for displaying.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and apparatus for detecting deterioration of an insulation-coated electric wire for nondestructively detecting deterioration of the insulation coating of the insulation-coated electric wire.

[0002]

2. Description of the Related Art Conventionally, as a method or apparatus for detecting deterioration of an insulation-coated electric wire, there is Japanese Utility Model Laid-Open No. 61-131674. That is, as shown in the inspection example in FIG. 8, a plurality of linear electrodes 103 are provided on the surface of the insulating coating 102 of the insulating coated electric wire.
In the state where they are in contact with each other, a voltage is applied between the core wire 101 and the insulation coating 102 of the insulation-coated electric wire,
When the linear electrode 103 enters the crack portion 106 of the insulating coating 102 where 01 is exposed, the power source 105 causes the detector 1
There is a device in which the detector 104 detects the energized state by applying electricity to the ground 107 through the wire 04, the linear electrode 103, and the core wire 101 of the insulation-coated electric wire.

[0003]

This method utilizes mechanical contact between the core wire 101 of the insulation-coated electric wire and the linear electrode 103, and therefore cannot detect cracks or fine cracks in a closed crack state. In addition, since a detection current flows through the core wire 101 of the insulation-coated electric wire when energized, it is difficult to apply it to the working wire, and only cracks on the scanning line of the linear electrode 103 can be detected, and insulation of the insulation-coated electric wire is detected. There was a problem that it was difficult to inspect the coating 102 in the circumferential direction without unevenness.

The present invention was proposed in order to improve the above-mentioned drawbacks, and its purpose is to measure an insulation-coated electric wire in a nondestructive manner and to measure the degree of deterioration of the insulation coating uniformly and simply and quantitatively. An object of the present invention is to provide a method and an apparatus for detecting deterioration of an insulated covered electric wire that can be grasped.

[0005]

In order to achieve the above object, a method for detecting deterioration of an insulating coated electric wire according to the present invention is to measure cracks in the insulating covered electric wire and measure the degree of deterioration of the insulating covering. Is a method of detecting, a uniform irradiation in a predetermined range in the longitudinal direction of the electric wire, an optical sensor for measuring the reflected light from the insulating coating surface in the longitudinal direction of the electric wire as a light intensity distribution waveform, and the light The intensity distribution waveform is digitally converted, and a conversion unit that converts the intensity distribution waveform into a reflection intensity sequence that is a data sequence of luminance values is provided, and the degree of deterioration of the insulating coating is based on the reflection intensity sequence and a predetermined deterioration determination reference luminance value. First to calculate
And a second step of displaying the degree of deterioration on the display unit.

Further, the optical sensor is configured to measure the light intensity distribution waveform at a plurality of locations on the circumference of the electric wire, and the conversion unit digitally converts the plurality of light intensity distribution waveforms. , A plurality of the reflection intensity sequences, and the first step calculates a deterioration degree of the single insulation coating based on the plurality of reflection intensity sequences and the predetermined deterioration determination reference luminance value. It is characterized by doing so.

Further, the method for detecting deterioration of an insulation-coated electric wire according to the present invention comprises a deterioration determination table for determining the degree of deterioration of the insulation coating from the relationship between the number of cracks in the insulation coating and the crack width, and the first step. Is a third step of creating a histogram of the brightness value from the reflection intensity sequence, a fourth step of calculating a threshold value which is a crack determination reference value based on the histogram, and a reflection intensity sequence of the reflection intensity sequence. Each brightness value is a crack location that is lower than the threshold value is specified, the total number of crack locations, the number of cracks, the width of the crack location is determined as the crack width, and the maximum crack width is the maximum width. And a sixth step of obtaining the degree of deterioration by referring to the deterioration determination table with the number of cracks and the maximum crack width.

The method for detecting deterioration of an insulation-coated electric wire according to the present invention further comprises a deterioration determination table for determining the degree of deterioration of the insulation-coated electric wire based on the relationship between the number of cracks and the crack width of the insulation coating. The step includes a seventh step of creating a plurality of histograms (H ₁ , H ₂ , ..., H _n ) of the brightness values from the plurality of reflection intensity sequences, and the histogram (H
, H _n ) based on ₁ , H ₂ , ..., H _n ) and the threshold values (I _th1 , I _th2 , ...
8 th step of calculating I _thn ), and for each of the reflection intensity rows, a crack location where each luminance value of the reflection intensity row is lower than the threshold value is specified, and the total number of the crack locations is determined. Is calculated as the number of cracks, and the width of the crack portion is calculated as the crack width, and the maximum crack width that maximizes the width is calculated, and the number of cracks (x ₁ ,
x ₂ , ..., X _n ) and the maximum crack width (d _max1 , d _max2 ,
_,, d _maxn ) and a plurality of maximum crack widths (d _max1 , d _max2 , obtained in the ninth step)
, D _maxn ) and the maximum crack width (d _max ) and the number of cracks (x) among the number of cracks (x ₁ , x ₂ , ..., X _n ) are referred to the deterioration determination table to determine the degree of deterioration. And a tenth step of:

As the threshold value, a luminance value I _max having the highest appearance frequency is obtained from the histogram, and the histogram is traced in the direction of decreasing the luminance value from the brightness value I _max, and the appearance frequency is first. The brightness value I _raise
And a brightness value (I _raise / 2) intermediate between brightness values of zero.

The insulation-coated electric wire deterioration detecting device of the present invention is a device for measuring cracks in the insulation-coated electric wire and detecting the degree of deterioration of the insulation coating. An optical sensor for uniformly irradiating a predetermined range in the longitudinal direction of the electric wire and measuring reflected light from the insulating coating surface in the longitudinal direction of the electric wire as a light intensity distribution waveform,
The main body unit digitally converts the light intensity distribution waveform and converts it into a reflection intensity sequence that is a data sequence of luminance values, a storage unit that stores the reflection intensity sequence, the reflection intensity sequence and a predetermined crack. It is characterized by comprising a processing unit for calculating the degree of deterioration of the insulating coating based on a threshold value which is a judgment reference value, and a display unit for displaying the degree of deterioration.

The measuring unit is an optical device for measuring the light intensity distribution waveform in a predetermined range in the longitudinal direction of the electric wire on the inner side surface of a divided member that divides the electric wire in the longitudinal direction from the circumferential direction. It is characterized in that a plurality of sensors are provided.

In addition, the deterioration detecting device for an insulating covered electric wire according to the present invention comprises a deterioration judging table for determining the degree of deterioration of the insulating covered electric wire based on the relationship between the number of cracks and the crack width of the insulating covering. Is a means for creating a histogram of at least one of the brightness values, a means for calculating at least one of the threshold values from the histogram, and a position where each brightness value of the reflection intensity sequence is lower than the threshold value. By specifying a certain crack location, the total number of the crack locations is the number of cracks, the width of the crack location is determined as the crack width, the maximum crack width at which the width is maximum is determined, and the number of the cracks and the maximum crack width And a means for obtaining the degree of deterioration by referring to a deterioration determination table.

Further, in the optical sensor, a light emitting element composed of a photodiode or a laser diode and a light receiving element composed of a CCD element are arranged in a predetermined range in the longitudinal direction of the electric wire in a direction orthogonal to the longitudinal direction of the electric wire. It is characterized in that a plurality of the optical sensors arranged in (1) are arranged in the predetermined range. Further, the deterioration detecting apparatus for an insulated covered electric wire according to the present invention is characterized in that the measuring section and the main body section are integrated.

[0014]

With the above means, the present invention can perform the nondestructive inspection quickly and easily because the measurement can be performed only by bringing the optical sensor into contact with the surface of the insulating covered electric wire. Further, by appropriately disposing a plurality of optical sensors, inspection can be performed in the circumferential direction without unevenness.

Furthermore, since the brightness level of the crack is relatively determined from the brightness level of the coating color of the cable, the crack detection independent of the cable color is possible. In addition, since the deterioration of the insulating coating is quantified from the frequency of occurrence of surface cracks, it is possible to perform deterioration diagnosis that does not depend on the subjectivity or skill of the inspector.

[0016]

Embodiments of the present invention will now be described in detail with reference to the drawings. One embodiment of the present invention will be described by taking a deterioration detection method for a CCP (color coded polyethylene) cable used for telecommunication as an example.

FIG. 1 is a block diagram of a deterioration detecting device which realizes a method of detecting deterioration of an insulated wire according to the present invention. The deterioration detecting device includes a main body 1 and a measuring unit 2. The main body 1 and the measuring unit 2 may be integrally configured. Further, the measuring unit 2 may be configured to include a plurality of optical sensors 4 on the inner surface of a divided member that divides the insulated coated electric wire 3 in the longitudinal direction from the circumferential direction.

Inside the measuring section 2, a plurality of optical sensors 4 for measuring the surface of the insulating coating are arranged. In this example, a case will be described in which four optical sensors 4 are used and are arranged so as to face each other, and the light emitting elements and the light receiving elements are arranged in pairs in a direction orthogonal to the longitudinal direction of the insulating covered electric wire 3.

As shown in FIG. 2, the main body 1 further includes an A / D converter 7 for converting an input signal from each optical sensor 4 from analog to digital, and a waveform stored as digital signal data (waveform data). A storage device 8, a calculation device 9 that performs a predetermined calculation on the waveform data to detect cracks and determine the degree of deterioration, a deterioration degree reference database 10 that stores data for determining the degree of deterioration, and an output of the determination result. It is composed of an output device 11 for performing. The optical sensor 4 is
It is composed of a pair of a plurality of light emitting elements 5 and light receiving elements 6 arranged so as to be linearly arranged along the longitudinal direction of the measured electric wire (in this example, a case where 2048 elements are arranged will be described. ).

A laser diode or a photodiode is used as the light emitting element 5, and a plurality of light emitting elements 5 are arranged linearly or a lens is used to emit light so as to uniformly irradiate the insulated wire 3 within the range to be measured. You may spread in a linear direction.

A CCD element is used as the light receiving element 6 so that light in the linear direction can be finely received. As shown in FIG. 2, the structure of the optical sensor 4 is such that the light emitting element 5 and the light receiving element 6 are arranged in the lateral direction.

That is, the insulation covered electric wire 3 is sandwiched between the measuring parts 2,
The light emitted from the light emitting element 5 of the optical sensor 4 uniformly illuminates a predetermined range in the longitudinal direction of the insulation-coated electric wire 3 by the light, and the measurement light L reflected from the surface of the insulation-coated electric wire 3 in the longitudinal direction is optically sensored. Light is received by the light receiving element 6 of 4 and measured as a light intensity distribution waveform. The light intensity distribution waveform measured by the optical sensor 4 is digitally converted into a reflection intensity sequence which is a data sequence of luminance values. The deterioration degree of the insulation coating is calculated based on the reflection intensity sequence and a predetermined deterioration determination reference value. In this case, the portion of the reflection level of the reflection intensity sequence that is lower than the crack determination level that is the deterioration determination reference value is regarded as the crack portion. Deterioration is diagnosed by calculating the degree of deterioration based on the number of cracks and the crack width.

The measuring unit 2 is constructed so that the optical sensor 4 and the insulating covered electric wire 3 are in contact with each other so that external light does not enter. In the case of a telephone wire, the upper limit of the width of the measuring section 2 (longitudinal direction of the insulation-coated electric wire 3) is about 6 cm. When measuring the insulation-coated electric wire 3 in the connection terminal box,
It is based on the length that can be straightened so that it can be measured.

The degree of deterioration is displayed on a display section (7-segment LED or the like) provided on the output device 11 of the main body section 1. When the deterioration degree is displayed as a character string, it is naturally possible to display "Trica frog, Alymus" or the like by using the same display unit as the pager.

Further, the present apparatus does not use a movable part which increases power consumption and manufacturing cost. FIG. 3 is an operation flow of the deterioration detecting device of the present invention. As shown in FIG. 1, the electric wire 3 to be measured is sandwiched between the measuring sections 2, and the surface state of the insulating coating is linearly measured along the longitudinal direction by the four optical sensors 4 arranged to face the measuring section 2 (measuring step). ).

The received analog signal is subjected to a predetermined gradation (25 in this example) by the A / D converter 7 for each measurement series.
It is quantized into 6 gradations and converted into a digital signal (A /
D conversion step), and is further stored in the waveform storage device 8 as a waveform data string S _n (n = 0 to 2047) (waveform storage step). FIG. 4 shows an example of waveform data of the deteriorated insulation-coated electric wire 3. (A) shows the appearance of the electric wire 3 to be measured, and dotted lines aa 'in the figure are scanning lines measured by the light emitting and light receiving elements 5 and 6. (B) shows the measured waveform data, the horizontal axis is the number of scanning pixels, and the vertical axis is the luminance value. The crack generated on the insulating coating due to the deterioration lowers the brightness value at that position due to the shadow. Note that the brightness value does not always become constant even on a healthy coating, and the value fluctuates due to the effects of stains, color unevenness, and the like.

The arithmetic unit 9 counts the number of appearances for each brightness value from the waveform data and creates an appearance frequency distribution (hereinafter referred to as a histogram) (waveform analysis step 1). FIG. 5 shows FIG.
It is a histogram obtained from the waveform data shown in (b). The horizontal axis is the luminance value i, the vertical axis represents the cumulative number n _i of the number of occurrences of luminance values. In the figure, the distribution lump 1 reflects the color of the ground of the insulating coating, and the distribution lump 2 reflects the color of the shadow due to the crack.

Further, the arithmetic unit 9 automatically calculates the threshold level I _th for distinguishing the ground and the crack of the insulating coating by the following method (waveform analysis step 2). First, a luminance value I _max that gives the maximum cumulative number (maximum appearance frequency) is obtained from the histogram, then, when the histogram is traced in the direction in which the luminance value decreases from I _max , the point at which the cumulative number first becomes zero is found. It is detected, and the intermediate value between the brightness value I _{raise at} that point and the brightness value 0 is defined as I _th (= I _raise / 2, and this crack determination reference value is hereinafter referred to as a threshold value).

In the histogram of FIG. 5, the luminance value (I
max) appears in the luminance value corresponding to the color of the insulated wire 3. Therefore, if the coating color is “white”, the level is high, and the crack can be easily determined. However, if the coating color is a dark color, the level is low, and thus the determination of the crack is difficult.
Based on these, the threshold value is I _raise so that the crack can be surely determined even when the coating color is a dark color.
It is calculated as / 2. Since the threshold value varies depending on the coating color in this manner, cracks can be measured even in a telephone line cable in which a plurality of coating colors are mixed.

Next, the arithmetic unit 9 counts the number of locations in the waveform data where the luminance value is lower than the threshold level, and further measures the maximum value of its width (pixel number). (Waveform analysis step 3). These values are regarded as the number of cracks and the maximum crack width, respectively. FIG. 6 is an explanatory diagram showing how a crack is detected from waveform data and a threshold value. (A) is the waveform data, and the luminance value I _th shown by the dotted line in the figure is the threshold level. (B) shows the results of detection of cracks and crack widths, where there are three cracks and the maximum crack width is three pixels (dots).

Based on the value, the arithmetic unit 9 refers to the deterioration determination table which is made into data in advance in the deterioration degree reference database 10, and allocates the deterioration degree to each measurement series from the detected number of cracks and the maximum crack width. (Database reference process). FIG. 7 shows a deterioration judgment table used for judging deterioration of the insulation coating of the CCP cable. The degree of deterioration is uniquely determined from the distribution range of the number of cracks and the maximum crack width with respect to deterioration of the insulating coating. Table 1 shows the relationship between the degree of deterioration and its state.

[0032]

[Table 1]

Finally, the arithmetic unit 9 selects the largest degree of deterioration from the degrees of deterioration assigned to each measurement series, and determines it as the degree of deterioration of the wire to be measured (deterioration determining step). Output device 1
1 outputs and displays the deterioration degree (result output).

Next, regarding this embodiment, Table 2 shows the structure of the deterioration determination table of the deterioration degree reference database, and Table 3 shows the structure of the waveform data in the waveform storage device. Table 4 shows an example of the waveform data corresponding to FIG.

[0035]

[Table 2]

[0036]

[Table 3]

[0037]

[Table 4]

The light receiving element number of the waveform data is not an essential item. The brightness value may be stored corresponding to the address of the memory of the waveform storage device 8. Even when a plurality of optical sensors 4 are installed, an address may be assigned to each sensor. When a plurality of optical sensors 4 are installed, waveform data is created by allocating an address to each sensor, and the crack width and the number of cracks, which are parameters for obtaining the degree of deterioration, are the maximum measured from each sensor. . For example, when the number of cracks and the maximum crack width are measured by the optical sensors 4 of # 1 to # 4 as described below, the deterioration degree is calculated using the underlined value.

[0039] By adopting the maximum value in this way, the degree of deterioration is strictly determined (high safety factor).

That is, a plurality of light intensity distribution waveforms measured by the optical sensor 4 are digitally converted into a plurality of reflection intensity sequences which are data sequences of corresponding brightness values. A plurality of brightness value histograms (H ₁ , H ₂ , ..., H _n ) are created from the plurality of reflection intensity sequences. Based on this histogram (H ₁ , H ₂ , ..., H _n ), threshold values (I _th1 , I _th2 ,
, I _thn ) is calculated. For each of the reflection intensity columns, each brightness value of the reflection intensity column is specified as a crack location that is lower than the threshold value, and the total number of the crack locations is the number of cracks,
The width of the cracked portion is determined as the crack width, the maximum crack width that maximizes the width is determined, and the number of cracks (x ₁ , x ₂ , ..., X _n
) And the maximum crack width (d _max1 , d _max2 , ..., D _maxn ). The plurality of maximum crack widths (d _max1 , d _max2 , ...,
d _maxn ) and the number of cracks (x ₁ , x ₂ , ..., X _n ) and the maximum maximum crack width (d _max ) and the number of cracks (x) are referred to the deterioration determination table to determine the degree of deterioration.

[0041]

As described above, according to the present invention, it is possible to perform a judgment action which has been dependent on the experience and skill of the inspector.
It can be performed absolutely and quantitatively by a machine. Further, since it is an optical measurement, it is non-destructive and can be easily and promptly measured in the circumferential direction without unevenness. Furthermore, in the present invention, since the crack detection level is appropriately selected for each measurement, deterioration can be detected without depending on the color of the insulating coating.

[Brief description of drawings]

FIG. 1 is a perspective view showing an embodiment of the present invention.

FIG. 2 is a configuration explanatory view showing an internal configuration of a deterioration detection device according to an embodiment of the present invention.

FIG. 3 is a flowchart showing a processing flow of a deterioration detecting method according to an embodiment of the present invention.

FIG. 4 is a diagram schematically showing one of waveform data obtained when a deteriorated insulation-coated electric wire according to an embodiment of the present invention is measured. FIG. The measurement line, (b) shows the measured waveform data.

FIG. 5 is an explanatory diagram showing a histogram and threshold values obtained from waveform data according to an embodiment of the present invention.

6A and 6B are schematic diagrams showing how a crack is detected from waveform data and a threshold value according to an embodiment of the present invention, FIG. 6A shows waveform data, and FIG. 6B shows a detection result of a crack and a crack width.

FIG. 7 is a deterioration determination table that determines the degree of deterioration when diagnosing the insulation coating of the CCP cable according to the embodiment of the present invention.

FIG. 8 is an explanatory diagram showing a deterioration detection method by a conventional energization method.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Main body part, 2 ... Measuring part, 3 ... Insulated coating electric wire, 4 ... Optical sensor, 5 ... Light emitting element, 6 ... Light receiving element, 7 ... A / D converter, 8 ... Waveform storage device, 9 ... Arithmetic device, 10 ... deterioration degree reference database, 11 ... output device.

Front page continuation (72) Inventor Hiroaki Shindo 1-6, Uchisaiwaicho, Chiyoda-ku, Tokyo Nihon Telegraph and Telephone Corporation (72) Inventor Junichi Masuda 1-6, Uchisaiwaicho, Chiyoda-ku, Tokyo Nihon Telegraph Phone Co., Ltd.

Claims (10)

[Claims] 1. A method for measuring the degree of deterioration of the insulating coating by measuring cracks in the insulating coating of an electric wire coated with the insulating coating, the method comprising uniformly irradiating a predetermined range in the longitudinal direction of the electrical wire, An optical sensor that measures reflected light from the insulating coating surface in the longitudinal direction of the electric wire as a light intensity distribution waveform, and a conversion unit that digitally converts the light intensity distribution waveform and converts it into a reflection intensity sequence that is a data sequence of luminance values. A first step of calculating the degree of deterioration of the insulating coating based on the reflection intensity sequence and a predetermined deterioration determination reference luminance value; and a second step of displaying the degree of deterioration on a display unit. A method for detecting deterioration of an insulation-coated electric wire, comprising: 2. The optical sensor is configured to measure the light intensity distribution waveform at a plurality of locations on the circumference of the wire, and the conversion unit digitally converts the plurality of light intensity distribution waveforms. , A plurality of the reflection intensity sequences, and the first step calculates a deterioration degree of a single insulation coating based on the plurality of reflection intensity sequences and the predetermined deterioration determination reference luminance value. The method for detecting deterioration of an insulated covered electric wire according to claim 1, wherein the method is as described above. 3. A deterioration determination table for determining the degree of deterioration of the insulation coating from the relationship between the number of cracks and the crack width of the insulation coating, wherein the first step comprises a histogram of the brightness values from the reflection intensity column. And a fourth step of calculating a threshold value that is a crack determination reference value based on the histogram, and each luminance value of the reflection intensity sequence is lower than the threshold value. The number of cracks, the number of cracks, the total number of cracks, the width of the cracks is determined as the crack width, and the fifth step of determining the maximum crack width at which the width is maximum, and the number of cracks A sixth step of obtaining the degree of deterioration by referring to the deterioration determination table with the maximum crack width, the deterioration detecting method of the insulated covered wire according to claim 1. 4. A deterioration determination table that determines the degree of deterioration of the insulation-coated electric wire from the relationship between the number of cracks and the crack width of the insulation coating, wherein the first step comprises the luminance from the plurality of reflection intensity columns. histogram values _{(H 1, H 2, ...} , H n) and a seventh step of creating multiple, the histogram _{(H 1, H 2, ...} , H n) on the basis of, on the histogram one-to-one Eighth step of calculating the corresponding threshold value (I _th1 , I _th2 , ..., I _thn ), and for each reflection intensity row, each luminance value of the reflection intensity row is lower than the threshold value. A crack location that is a location is specified, the total number of the crack locations is determined as the number of cracks, and the width of the crack location is determined as the crack width, and the maximum crack width that maximizes the width is determined, and the number of cracks (x ₁ , x ₂ , ..., X _n ) and the maximum crack width (d
_max1, d _max2, ..., a ninth step of obtaining a d _maxn), said ninth multiple maximum crack width obtained in step _{(d max1, d max2, ...} , d maxn) and number of cracks (x _1, x
₂ , ..., X _n ), and a tenth step of obtaining the degree of deterioration by referring to the deterioration determination table with the maximum maximum crack width (d _max ) and the number of cracks (x). The method for detecting deterioration of an insulated covered electric wire according to claim 2. 5. The threshold value is a luminance value I that maximizes the frequency of appearance from the histogram.
_max is calculated, the histogram is traced in the direction of decreasing the brightness value from the brightness value I _max, and the brightness value I _{raise at} which the appearance frequency becomes zero first and the brightness value (I
_The method of detecting deterioration of an insulated covered wire according to claim 3 or 4, wherein the method is set to _raise / 2). 6. A device for measuring cracks in an insulation-coated electric wire to detect a degree of deterioration of the insulation coating, wherein the measuring unit uniformly covers a predetermined range in the longitudinal direction of the electric wire. An optical sensor that irradiates and measures reflected light from the insulating coating surface in the longitudinal direction of the electric wire as a light intensity distribution waveform is provided, and the main body unit digitally converts the light intensity distribution waveform, and in a data string of luminance values. Based on the conversion unit for converting to a certain reflection intensity sequence, a storage unit that stores the reflection intensity sequence, and the threshold value that is the reflection intensity sequence and a predetermined crack determination reference value, the deterioration degree of the insulating coating. A deterioration detecting device for an insulated covered electric wire, comprising: a processing unit for calculating; and a display unit for displaying the deterioration degree. 7. The optical unit for measuring the light intensity distribution waveform in a predetermined range in the longitudinal direction of the electric wire on an inner surface of a divided member that divides the electric wire in a longitudinal direction from a circumferential direction. The deterioration detecting device for an insulated covered electric wire according to claim 6, wherein a plurality of sensors are provided. 8. A deterioration determination table for determining the degree of deterioration of the insulation-coated wire from the relationship between the number of cracks and the crack width of the insulation coating, wherein the processing unit creates a histogram of at least one of the brightness values. Means for calculating at least one of the threshold value from the histogram, each luminance value of the reflection intensity column, to identify a crack location that is lower than the threshold value of the crack location The total number of cracks, the width of the crack location is determined as the crack width, the maximum crack width that maximizes the width is determined, and the deterioration degree is determined by referring to the deterioration determination table with the number of cracks and the maximum crack width. The deterioration detecting apparatus for an insulated covered electric wire according to claim 6 or 7, further comprising: 9. The optical sensor comprises a light emitting element made up of a photodiode or a laser diode and a light receiving element made up of a CCD element within a predetermined range in the longitudinal direction of the electric wire in a direction orthogonal to the longitudinal direction of the electric wire. 9. The deterioration detecting device for an insulated covered wire according to claim 6, 7 or 8, wherein a plurality of the optical sensors arranged in (1) are arranged in the predetermined range. 10. The deterioration detecting device for an insulated coated electric wire according to claim 9, wherein the measuring unit and the main body unit are integrated.