JPH08327534A - Inspection method and inspection device for optical reflection type in-liquid particle concentration detector - Google Patents

Abstract

PURPOSE: To provide an inspection method and an inspection device capable of accurately and efficiently inspecting or adjusting an in-liquid particle concentration detector using total reflection. CONSTITUTION: The inspection device 10 is equipped with a sample stage for setting an in-liquid particle concentration detector 20 as an inspection object, pressure contact members 11 to 13 capable of changing the total reflection intensity of inspection light 311 to such a value as corresponding to a pressing force in a state as pressed to the surface of wetted parts 251 to 253 without adhesion to a photoconductor 25, a drive means 14 for pressing the members 11 to 13 to the wetted parts 251 to 253 under a preset pressure, and a control means 15 connected to the inspection object device 20 and used for operating the drive means 14. The control means 15 operates the drive means 14, and the device 20 is inspected on the basis of an output value then available therefrom.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an inspection method and an inspection apparatus for a light reflection type in-liquid particle concentration detecting device for detecting the particle concentration in an inspection object liquid such as engine oil.

[0002]

2. Description of the Related Art In determining the deterioration of engine oil such as diesel engine, the amount of carbon particles contained in the oil is a powerful determination index. Then, an optical type particle concentration detecting device for liquid which measures a particle concentration contained in engine oil has been proposed. For example, as shown in FIG. 7, the in-liquid particle concentration detection device 90 applies the inspection light 31 to the first liquid contact surface 911 of the light guide body 91 whose tip is immersed in the inspection target liquid 81 such as engine oil. The optical sensor 93 detects the inspection light 311 which is incident and totally reflected by the second and third liquid contact surfaces 912 and 913. In FIG. 7, reference numeral 92 is the inspection light 31.
Is a light-emitting element that emits. The inspection light 311 detected by the optical sensor 93 is the inspection light 31 totally reflected by the first to third liquid contact surfaces 911 to 913, and its intensity changes depending on the particle concentration in the inspection target liquid 81.

When this particle concentration detection apparatus for liquid is inspected in a production line or the like, the liquid contact surfaces 911 to 913 are preliminarily prepared in a sample liquid (suspension or emulsion) having a predetermined particle concentration. Then, the quality of the device is judged based on the output value obtained at this time, or the constant of the operational amplifier of the device is adjusted so that the output value becomes a predetermined value.
This is because the non-defective particle concentration detection device for liquid must show a predetermined output value for a predetermined particle concentration of the liquid to be inspected.

[0004]

However, the above-mentioned conventional method for inspecting an in-liquid particle concentration detecting apparatus using a sample liquid mixed to a predetermined particle concentration has the following problems.
The reason is that when the liquid contact surface of the device is immersed in the sample liquid, particles or colloids in the liquid adhere to the liquid contact surface, which changes the output value and tends to cause variations. In particular, the carbon particles in the deteriorated engine oil easily attach to the liquid contact surface of the light guide formed of an insulating material such as glass or resin, which is a serious problem.

Further, there is a problem in that it is necessary to wash the liquid contact surface after the inspection, which requires extra man-hours. The present invention has been made in view of such conventional problems,
An object of the present invention is to provide an excellent inspection method and inspection device capable of accurately or efficiently inspecting or adjusting an in-liquid particle concentration detection device utilizing total internal reflection.

[0006]

A first invention of the present application is a method for inspecting an in-liquid particle concentration detecting apparatus for detecting a total reflected light on a liquid contact surface to detect a particle concentration in the liquid. The apparatus includes a light emitter that emits inspection light, a light guide that guides the inspection light to a liquid contact surface with a liquid to be inspected, and an optical sensor that detects the inspection light totally reflected by the liquid contact surface of the light guide. And a determination unit that determines the particle concentration by receiving the output signal of the optical sensor, and does not adhere to the light guide body, and is pressed against the surface of the liquid contact surface to detect the inspection light. A pressure contact member capable of changing the total reflection intensity to a value corresponding to the pressing force is prepared, and the pressure contact member is pressed against the liquid contact surface with a predetermined pressure, and by the output of the optical sensor or the determination unit at this time. Inspect the device for quality, or adjust the device so that the above output values have the desired characteristics. Lying in the inspection method of the liquid in the particle concentration detection apparatus according to claim to.

The most remarkable thing in the present invention is that
Prepare a pressure contact member that can change the total reflection intensity of the inspection light to a value corresponding to the pressing force by pressing it against the liquid contact surface, and press this pressure contact member against the liquid contact surface with a predetermined pressure. However, the quality of the device is inspected by the output of the optical sensor or the determination unit at this time, or the device is adjusted so that the output value has a desired characteristic.

The material of the pressure contact member depends on the liquid to be inspected. For example, when the liquid to be inspected is engine oil, it may be a rubber material, resin, clay, adhesive tape or the like having an appropriate hardness. When a pressure-contact member whose total reflectance at the liquid contact surface changes depending on the pressing force is used, the pressing force of the pressure-contact member is changed in multiple stages, and the device is inspected or adjusted at multiple points. It is possible to perform inspection and adjustment with higher accuracy.

For the same purpose, a plurality of pressure contact members made of materials having different pressing surfaces may be prepared, and the pressure contact members may be changed to perform a plurality of inspections or adjustments. In this case, different pressure contact members must cause different total reflections at the liquid contact surface. As a method of adjusting the output of the device, there is a method of adjusting the amplification factor or offset value of the operational amplifier.

On the other hand, the second invention of the present application is an inspecting apparatus for detecting a particle concentration in a liquid by detecting the total reflection light on the liquid contact surface, and the above-mentioned particle concentration detecting apparatus in the liquid. Is a light-emitting body that emits inspection light, a light guide that guides the inspection light to a liquid contact surface with the liquid to be inspected, and an optical sensor that detects the inspection light totally reflected by the liquid contact surface of the light guide. , A determination unit for determining the particle concentration by receiving the output signal of the optical sensor, the inspection device, the sample stage on which the in-liquid particle concentration detection device to be inspected is installed, and the light guide A pressure contact member that can change the total reflection intensity of the inspection light to a value corresponding to the pressing force by pressing against the surface of the liquid contact surface without adhering, and a predetermined pressure contact member on the liquid contact surface. Connected to the device to be inspected and the driving means that presses with the pressure of And a control means for operating, wherein the control means operates the driving means, and judges the quality of the device based on the output value of the inspection target device obtained at this time. It is in the inspection device of the medium particle concentration detection device.

What is most noticeable in the second invention is that
A pressure contact member capable of changing the total reflection intensity of the inspection light to a value corresponding to the pressing force by pressing the liquid contact surface, and a drive for pressing the pressure contact member against the liquid contact surface with a predetermined pressure. And means for controlling the drive means, which is connected to the device under inspection. Then, the control means operates the driving means, and judges the quality of the device based on the output value of the inspection target device obtained at this time.

[0012]

In the inspection method or the inspection apparatus according to the present invention, a pressure contact member capable of changing the total reflectance of the liquid contact surface is used instead of the conventional sample liquid adjusted to a predetermined particle concentration. Inspect and adjust. Since this press contact member is one which obtains a predetermined total reflectance by pressing the liquid contact surface with a constant pressure, it corresponds to a sample liquid having a constant particle concentration, and is replaced by a sample liquid to simulate the sample liquid.
It can be replaced.

The pressure contact member does not adhere to the liquid contact surface and therefore does not stain the liquid contact surface, so that the output value of the device does not vary as in the case of using the sample liquid. Further, unlike the case of using the sample liquid, the work of washing the liquid contact surface after the inspection and adjustment is not necessary. As described above, according to the first invention or the second invention, an excellent inspection method or inspection apparatus capable of accurately or efficiently inspecting or adjusting an in-liquid particle concentration detection apparatus utilizing total internal reflection is provided. You can do it.

[0014]

EXAMPLE In this example, as shown in FIG.
The inspection device 10 of the in-liquid particle concentration detection device 20 detects the total reflection light 311 at 253 and detects the particle concentration in the liquid. The in-liquid particle concentration detection device 20 includes a light-emitting body 21 that emits the inspection light 31 and a liquid contact surface 251-2 between the liquid to be inspected.
The light guide 25 for guiding the inspection light 31 to 53, and the light guide 25
The optical sensor 22 detects the inspection light 311 totally reflected by the liquid contact surfaces 251 to 253, and the determination unit 40 that receives the output signal of the optical sensor 22 to determine the particle concentration.

The inspection device 10 does not adhere to the sample stage (not shown) on which the in-liquid particle concentration detection device 20 to be inspected is installed and the light guide 25, and the liquid contact surfaces 251 to 253 are not attached. The pressing member 1 capable of changing the total reflection intensity of the inspection light 311 to a value corresponding to the pressing force by pressing.
1 to 13 and the pressure contact members 11 to 13 on the liquid contact surfaces 251 to 25
3 and a control means 1 for operating the drive means 14, which is connected to the inspection target device 20 and drives the drive means 14 with a predetermined pressure.
5 and 5. The control means 15 operates the drive means 14, and determines the quality of the device 20 based on the output value of the device 20 to be inspected obtained at this time.

A supplementary explanation will be given below for each of them.
The in-liquid particle concentration detection device 20 is an oil deterioration determination device that determines deterioration of engine oil, and the inspection device 10 is a device for adjusting the characteristics of the operational amplifier of the in-liquid particle concentration detection device 20. Luminescent body 2 of liquid particle concentration detector 20
As shown in FIG. 2, the inspection light 31 emitted from the LED 1 (LED) is not only guided to the liquid contact surfaces 251 to 253 of the light guide 25, but also reflected by the surface of the light guide 25 to be the reference light. There is monitor light 312 incident on the sensor 23.

Then, the optical sensor 22 and the reference optical sensor 2
The outputs of 3 (both are photodiodes) are amplified by operational amplifiers 43 and 44, respectively, and outputs V1 and V
As for 0, the ratio σ of the two is obtained in the divider 45. The ratio σ, that is, the total reflectance at the liquid contact surfaces 251 to 253 is compared with the reference value by the subsequent comparator 46, and when σ does not reach the predetermined level, it is determined that the engine oil is deteriorated and the alarm circuit 47 is used. An oil deterioration warning is issued. In the figure, a terminal TT is a test terminal for extracting a signal of the ratio σ, and a reference numeral 48 is a thermistor temperature sensor for detecting the oil temperature. Further, in FIG. 1, reference numeral 29 is a connector.

When the degree of deterioration of the oil is not judged in two stages of good and bad as described above but the degree of deterioration is judged in multiple stages, for example, a plurality of the comparators 46 are provided and each of the comparators 46 is provided. Determine the level of degradation separately. That is, for example, in the case of determining the deterioration degree in three stages, as shown in FIG.
At two points of, comparing with different reference values σs, σs',
As shown in steps 603 to 605, it is determined which of the deterioration degrees is 1 to 3. In addition, the light guide 25 of this example
Has a refractive index nd of 1.8061 and is NbFD15 (HOY
(Made by A).

The pressure contact members 11 to 13 of the inspection device 10 are made of acrylic rubber having a hardness of 48IRH, and have contact surfaces 251 to 251.
When it is pressed against 253, the liquid contact surface 251 is pressed according to the pressing force.
The total reflectance changes at ˜253. FIG. 3 illustrates changes in the output of the optical sensor 22 corresponding to the pressing force. As can be seen from FIG.
If the liquid contact surfaces 251 to 253 are pressed with a pressure of 0 Pa or more, the output (82%) of the optical sensor 22 at a substantially constant level can be obtained.

As shown in FIG. 1, the driving means 14 includes pistons 141 to 143 to which the pressure contact members 11 to 13 are mounted,
Hydraulic drive member 144 that drives the pistons 141 to 143
And the hydraulic drive member 144 has a control means 15
Operated by. The control means 15 is the hydraulic drive member 1.
44 to drive the pressure contact member 11 at a pressure exceeding 150 Pa.
13 to 13 are pressed against the liquid contact surfaces 251 to 253. Then, in order that the device output σ at this time (FIG. 2) becomes a predetermined value σs,
For example, the feedback resistance RV of the operational amplifiers 43 and 44 shown in FIG.
Adjust the value of (trimming resistance).

Alternatively, as shown in FIG. 5, when the output σ is outside the range of the predetermined value σs ± α, the device is defective (failed).
And outputs the determination result. As shown in FIG. 6, there are two deterioration level reference values (σs, σs ′), and when the quality of the device is determined or adjusted at two points, it corresponds to the above σs, σs ′. Using two types of pressure contact members, the pressure contact members 11 to 13 are replaced and the apparatus is adjusted or inspected twice.

In the inspection method and the inspection apparatus 10 of this example, the pressure contact members 11 to 13 capable of changing the total reflectance of the liquid contact surfaces 251 to 253 instead of the conventional sample liquid adjusted to a predetermined particle concentration. Use to inspect and adjust the device. The pressure contact members 11 to 13 have liquid contact surfaces 251 to 253.
Since a predetermined total reflectance can be obtained by pressing with a constant pressure, the sample solution can be simulated and replaced by a sample solution corresponding to a sample solution having a constant particle concentration.

Then, the above-mentioned 251 to 253 pressure contact members 11
No. to No. 13 do not adhere to the liquid contact surfaces 251 to 253, and therefore do not stain the liquid contact surfaces 251 to 253, so that the output value of the device does not vary as in the case of using the sample liquid. Further, unlike the case of using the sample liquid, the work of washing the liquid contact surfaces 251 to 253 after the inspection and adjustment is not necessary. As described above, according to the present example, it is possible to provide an excellent inspection method and inspection device capable of accurately or efficiently inspecting or adjusting the in-liquid particle concentration detection device 20 utilizing total internal reflection. .

[Brief description of drawings]

FIG. 1 is a system configuration diagram of a main part of an inspection device and a liquid particle concentration detection device according to an embodiment.

FIG. 2 is a circuit diagram of an in-liquid particle concentration detection device according to an embodiment.

FIG. 3 is a diagram showing the relationship between the pressing force of the pressure contact member and the output of the optical sensor according to the embodiment.

FIG. 4 is a circuit diagram of an operational amplifier according to an embodiment.

FIG. 5 is a flow chart of quality determination of the inspection apparatus of the embodiment.

FIG. 6 is a determination flowchart of an oil deterioration determination device that determines deterioration in multiple stages.

FIG. 7 is a system configuration diagram of a conventional particle concentration detecting device in liquid.

[Explanation of symbols]

 10. ． ． Inspection device, 11, 12, 13. ． ． Pressure contact member, 14. ． ． Drive device, 15. ． ． Control means, 20. ． ． Liquid particle concentration detector, 251, 252, 2553. ． ． Wetted surface, 31, 311. ． ． Inspection light,

Claims (6)

[Claims] 1. A method of inspecting an in-liquid particle concentration detecting apparatus for detecting total reflection light on a liquid contact surface to detect a particle concentration in the liquid, wherein the in-liquid particle concentration detecting apparatus emits inspection light. A light guide that guides the inspection light to the liquid contact surface between the light emitter and the liquid to be inspected, an optical sensor that detects the inspection light totally reflected by the liquid contact surface of the light guide, and an output signal of this optical sensor. The total reflection intensity of the inspection light corresponds to the pressing force by pressing against the surface of the liquid contact surface without adhering to the light guide body. Prepare a pressure contact member that can be changed to a value, press the pressure contact member against the liquid contact surface with a predetermined pressure, and inspect the quality of the device by the output of the optical sensor or the determination unit at this time, or The device is adjusted so that the output value has a desired characteristic. Inspection method of the medium particle concentration detection apparatus. 2. The liquid particle concentration detection device according to claim 1, wherein the liquid to be inspected is engine oil, and the pressing surface of the pressure contact member is formed of an elastically deformable rubber material. Inspection methods. 3. The method for inspecting an in-liquid particle concentration detecting device according to claim 1, wherein the pressing force of the pressure contact member is changed in multiple stages to inspect or adjust the device at a plurality of points. 4. The submerged liquid according to claim 1 or 3, wherein a plurality of pressure contact members made of materials having different pressing surfaces are prepared, and the pressure contact members are replaced to perform a plurality of inspections or adjustments. Inspection method of particle concentration detector. 5. The operational amplifier according to claim 1, wherein the determination section is provided with an operational amplifier that converts an output signal of the optical sensor, and the operation is performed so that desired device characteristics can be obtained. A method for inspecting an apparatus for detecting particle concentration in liquid, which comprises adjusting an amplifier. 6. An inspecting device for an in-liquid particle concentration detecting device for detecting total reflection light on a liquid contact surface to detect a particle concentration in the liquid, wherein the in-liquid particle concentration detecting device emits inspection light. A light guide that guides the inspection light to the liquid contact surface between the light emitter and the liquid to be inspected, an optical sensor that detects the inspection light totally reflected by the liquid contact surface of the light guide, and an output signal of this optical sensor. The inspection device has a determination unit for determining the particle concentration, and the inspection device is configured to contact the sample stage on which the in-liquid particle concentration detection device to be inspected is installed, without adhering to the light guide body. A pressure contact member capable of changing the total reflection intensity of the inspection light to a value corresponding to the pressing force by pressing the liquid contact surface, and a drive means for pressing the pressure contact member against the liquid contact surface with a predetermined pressure. And a control unit that is connected to the device to be inspected and operates the drive unit. Having the control means, by operating the drive means, to determine the quality of the device based on the output value of the device to be inspected obtained at this time, the inspection of the in-liquid particle concentration detection device apparatus.