JPS60247131A - Photoelectric recording method of pointer of pressure gage - Google Patents

Abstract

PURPOSE:To obtain a stable output even if rotation is changed, by using a conventional Bourdon gage, reading a value optically, obtaining the records of multiple channels for a long time, and electrically calibrating the pressure gage. CONSTITUTION:Modulated light from a light emitting diode 7a is projected on the surface of a pressure gage. The reflected light is received by a light receiving diode 7b. Then the signal is rectified by a rectifier 11 and wave form d-b is obtained. In this waveform, b1 is a judging mark, b2 is an original point mark and b3 is a light signal by a pointer. A time length (t) between b2 and b3 is a deflection degree of the pointer. Therefore, only b1-b3 can be taken out accurately. The detected signal is reset by a signal, which is obtained by delaying the judging mark by an FF in a delay circuit 18 using an original point and pointer detector 14. Then the signals of the original point and the pointer are inputted to a block of two FFs 14a and 14b. An AND value 14c of the outputs of the FFs is obtained. Then the time from the original point and the pointer is obtained as a pulse width. Thus time change of the pressure gage can be readily calibrated.

Description

[Detailed description of the invention] 11th grade prisoner for the first time in his life.

The present invention relates to a photoelectric recording method for a pressure gauge pointer, and more particularly to a rotary bomb type oxidation stability test recording method.

There is a rotating cylinder test method for testing the oxidation stability of turbine oil, etc., and one example is shown in Figure 3. In FIG. 3, a is a schematic configuration diagram of this rotary cylinder type oxidation stability tester, and b is a front view showing an example of a test type pressure gauge record on sickle paper.

In the figure, 1 is a cylinder that contains a sample container with a lid containing a sample, water and a copper catalyst coil, and also contains 6-5 kg/a of oxygen.
m” (620KPO) and placed in a constant temperature bath 2 at 150°C. Reference numeral 3 is a cylinder rotation motor which rotates the cylinder holder 4 through a coupling mechanism such as a gear, and places the cylinder 1 in a constant temperature bath 2. It is rotated at a speed of 100 revolutions per minute while maintaining the tilt at an angle of 30 degrees to promote the reaction between the sample and a certain amount of oxygen. This is transmitted to the Bourdon tube pressure gauge 5, and the change in pressure drop according to the oxygen reaction is plotted on a chart. be.

However, since the chart of such a conventional spring-type self-recording pressure gauge is a round type for 6 hours, the records overlap when measuring for a long time, making it difficult to judge the pressure time.

Furthermore, the conventional spring-type self-recording pressure gauge uses an ink pen and a jeweled needle while rotating to record on an ink chart or a carphone chart, so the contact between the chart and the pen is difficult. Moreover, recently there has been a demand for a recorder with a longer recording time, and there is a need to improve this.

Taking these points into consideration, the present invention utilizes the movement of the pressure gauge pointer and light to guide the movement of the light spot to the light receiving element, which extracts and records it as a DC voltage. In this case, the pressure gauge rotates with the cylinder, so the photodetector is fixed in front of the rotating pressure gauge.

In this way, this invention has fewer troubles because it is photoelectric and non-contact, and is light because there is no spring etc. in the 5-rotation section, and since the recording section does not rotate, it will occur if it continues without stopping midway.
Easy to handle.

By connecting a recorder such as a pen type or dot type to the analog output terminal, long-term multi-channel recording can be taken, and the pressure gauge can be calibrated electrically, so that it can be easily calibrated even when the rotation changes. Stable output can be obtained. Further, in this invention, a wide discrimination mark and an origin mark in the same shape as the pointer are provided on the scale plate of the pressure gauge, and the deflection from the origin mark to the pointer is detected in the optical detection circuit using the discrimination mark as a reference for discrimination. The time axis (pulse width) is 9, and it is further converted into an angle by taking the ratio to the time of one rotation.

1渭Uυ11Xing This invention will be explained with reference to the embodiments shown in the figures.

The first ffia is a side view of the pressure gauge that rotates as a VC together with the cylinder, the same figure is a front view, and the same figure C is a circuit block diagram for reading the signal that can be detected by light 9 against the pointer of the pressure gauge, the same figure It is a diagram of an optical signal read by dfl.

The pressure gauge 5 in the figure rotates as the cylinder 4 rotates, as shown in Figure 1. There is a pointer 5 on the scale plate of the pressure gauge 5.
In addition to a, a discrimination mark 5b having a relatively wide width and a needle-like narrow origin mark 5c are provided, and the interval between the origin mark 5c and the pointer 5a is t, which corresponds to a desired reading time width.

In addition, since there is a 00 point scale as a pressure gauge, zero adjustment is performed at the end of the photodetection circuit.

The existence of the discrimination mark 5b, which has a wide surface width, is confirmed to facilitate the desired reading.The light detection circuit uses the discrimination mark as a reference to determine the deflection from the origin mark to the pointer on the time axis (pulse width). ), and further converts it into an angle by taking the ratio with the time of one rotation. 7 is a photodetector whose details are omitted, but the light emitted from a light emitting diode is applied to the surface of the scale plate of the pressure gauge 5, and the returned light is received by a light receiving diode to detect a discrimination mark 5b, an origin mark 5c, and a pointer 58 of the pressure gauge. etc., and can output the optical signal 9 as shown in d of the same figure.

In this case, the discrimination mark is 5 to 10 times wider than the needle, and the origin mark is the same width as the needle. The scale on the outer periphery is left at a minimum, and the rest is white to reflect light.
In addition, a reflection type photodetector 7 is fixed on the front side of the rotating pressure gauge 5 at a position where it scans the vicinity of the dotted line in FIG.
Since the signal seen in this way becomes a signal that is difficult to distinguish due to external disturbances (indoor natural light), etc., the brightness of the light emitting diode 7a included in the reflective photodetector 7 is approximately 4 KH2 in the Patch diagram of FIG. 1C. A signal that turns the frequency signal on and off is added. In other words, a frequency signal of approximately 4KH2 that can be oscillated by the oscillator 8 is transmitted to the transistor switch SW.

The light emitting diode 7a is turned on and off to apply modulation to the light emitting diode 7a.

In this way, the modulated light from the light emitting diode 7a hits the surface of the pressure gauge 5, and the reflected light is sent to the light receiving diode 7.
Capture it with b.

However, since this optical signal has been modulated at 4KH2, it is passed through a filter 9 through which signals of 4KH2 or higher pass to restore it to its original state, and then amplified by an amplifier 10 to obtain the waveform shown in FIG. 1d-a.

Next, this harmonic signal is rectified through the rectifier 11, resulting in the waveform shown in FIG. 1d-b.

This waveform is the discrimination mark + bt is the origin mark +
J hails the light signal from the needle-b, , b.

The time width t in between is the degree of deviation of the pointer, and T is one revolution.

Therefore, only the five signals S, B, and B (However, since S is only used to determine the origin, the number of signals to be removed by the photodetection circuit can be accurately determined).

Next, reference numeral 12 denotes a discrimination mark detection circuit, in which the discrimination mark can be detected from the output of the rectifier 11 by taking advantage of the fact that the width of the discrimination mark is 5 to 10 times wider than the needle or origin mark. At the same time, 15 is a circuit for detecting the center point of the needle and the origin mark, to which the output of the rectifier 11 is added, and its output is shown in Figure 2 d.
-c ゛The rising 9 edge of this pulse is almost the center point.

The reason is that when the rectified signal is differentiated as shown in FIG. 2a, a signal whose center point (peak point) intersects Ov is obtained as shown in the figure.

When this signal is passed through a comparator with a threshold voltage near OV, a rectangular wave is seen as shown in Figure C, and the rising edge of this pulse is the center point of the pulse. The advantage of detecting the center point in this way is the shape of the distance needle between the pressure gauge 5 and the photodetector 7.

This is because even if the signal dispersion or level changes at the time of rectification due to the distance from the center of rotation of the photodetector 7 or deformation of the scale plate, it can be accurately captured by detecting the center point.

For example, for the modulated waveform in Figure 2 d, if the rectified waveform is input to a comparator, it will become as shown in Figure 2 e and f, but if center point detection is used, the rising edge of the pulse will be at the center as shown in Figure 2 f and h. It becomes a point and can be captured accurately. Using the signals of the discrimination mark, origin mark and needle detected in this way, the origin-needle detector 14 uses a flip-flop to first reset the discrimination mark with a signal delayed by one day in the delay circuit, and then By putting the origin and needle signals into the block inputs of the two 7-lip flop blocks 14a and 14b and taking the AND 14Q of these outputs, needle 1 is moved from the origin.
The time at is seen as the pulse width.

Note that circuit 1 is used to detect the center point to delay the discrimination mark.
When performing differentiation in step 5, the discrimination mark is also differentiated and appears in the output, so this part needs to be removed. Therefore, in terms of a scale plate, the flip-flops 14a and 14b are reset and removed with a delay within the angle range from the origin mark to the 0 point. Next, this signal is CR-integrated by an integrator 15 and taken out as a DC voltage.

This voltage is proportional to the time from the origin to the needle during one revolution.

If there is no uneven rotation during one rotation, this time, that is, the DC voltage, is proportional to the angle from the origin to the needle.

The advantage of applying this rectangular wave to DC conversion circuit using the integrating circuit 15 is that even if the position of the photodetector from the center of rotation changes or the number of rotations changes slightly, the distance from the origin to the needle during IP1 rotation is constant. The ratio of is always constant.

From the DC voltage seen in this way, subtract the angle from the origin mark to 0 on the pressure gauge (perform 0 adjustment 17)
Span adjustment according to the recorder, etc. (iJ adjustment of the entire rotation) 1
By doing 6, any voltage from the pressure gauge 00 to full scale can be output as 9. By performing this zero adjustment and span adjustment electrically, the pressure gauge can be easily calibrated due to aging. Also, it can be freely adjusted to the scale of the recorder and recording paper. Also, the observed DC voltage Vbc is.

Vl)c=VX- (V is constant at the height of the rectangular wave), and the angle from the origin mark to the pointer is taken out as a DC voltage.

As you can see from the above formula, even if the rotation speed changes.

Furthermore, even if the sensor position changes from the center to the outer periphery, the output voltage remains constant, so a stable output voltage can be obtained.

Also, to create the above-mentioned rectangular wave, the origin mark is actually set in the same shape as the pointer, and the center point (peak value) of the signal obtained from this and the center point of the pointer are detected to create a rectangular wave. Errors caused by the width of the pointer can be eliminated.

11! False 1 - Flaws According to this invention, the conventional Bourdon tube pressure gauge is used and it is read optically, which makes it inexpensive, and by connecting a recorder such as a pen type dot type to the analog output terminal, Long-term multi-channel recording is possible. In addition, the pressure gauge can be calibrated electrically, making it unaffected by ambient light, and the position of the photodetector is not affected by errors, making it easy to install, and even if one rotation changes, it will not be affected by 50γpm to 200pm.
Stable output can be obtained within the range of γpm.

[Brief explanation of drawings]

Figures 1a and 1b are side and front views of only the pressure gauge. C is a circuit block diagram for reading the photodetection output. d-a=d'-G is an optical signal waveform diagram to be read. Figure 2 a - c is the theory of differential waveforms F! Figures A and d-h are waveform explanatory diagrams for comparison between the case where the rectified waveform is directly input into the comparator and the case where it is observed by center point detection. Figure 5a is a schematic diagram of a conventional rotary cylinder type oxidation stability tester, and also shows one of the records on the i-' type pressure gauge recording paper.
FIG. 3 is a front view of an example. 10 is an amplifier, 11 is a rectifier, 12 is a discrimination mark detector/ller, 15 is a center point detector, 74 is an origin point.
A needle detector, 15 an integrator, 16 a span adjuster, 17 a zero point adjuster, and 18 a delay circuit. Figure 2 C-Low

Claims (3)

[Claims] (1) When a cylinder is rotated and a pressure corresponding to the degree of oxidation of a sample placed in a sample container in the cylinder is read out using a pressure gauge pointer, a photodetector is provided opposite to the pressure gauge,
A photoelectric recording method for a pressure gauge pointer, characterized in that the movement of light relative to the pointer is used to guide the movement of a light spot to a light receiving element, convert it into an electrical signal, and record it as a DC signal. (2) A rotating pressure gauge (with a fixed photodetector facing the attached pointer), so that the light from the photodetector is directed along the circumference of the scale plate of the pressure gauge and is received by the photodetector. A photoelectric recording method for a pressure gauge pointer according to claim 1, characterized in that: (3) A wide discrimination mark and an origin mark in the same shape as the pointer are applied to the scale plate of the pressure gauge, and the deflection from the origin mark to the pointer is measured over time using the discrimination mark as a criterion for discrimination in the optical detection circuit. 2. A photoelectric recording method for a pressure gauge pointer according to claim 1, characterized in that it is taken as an axis (pulse width) and further converted into an angle by taking a ratio with the time of one rotation.