JPS595855B2 - Refractometer or similar device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a refractometer or similar device, and in particular, to a refractometer or similar device, in particular a sample cell on a refracting prism is irradiated with light from a light source lamp to form a contrast image of refracted light on a photodetector. The present invention relates to a refractometer or similar device for determining the refractive index or specific gravity of a sample.

FIG. 1 shows a conventional refractive index hydrometer that measures the specific gravity of urine, etc. by applying the refractive index of light.

In the figure, 1 is a light source lamp, 2 is a sample, 3 is a sample cell, 4 is a refracting prism, 5 is an objective lens, and 6 is a transmission rhinometer. In such a refractive index hydrometer, the measurement sample 2 is dropped onto the refraction prism 4, the light from the light source lamp 1 is applied to the refraction prism 4, and the refraction of the measurement sample 2 is observed in the dark field by the objective lens 5. Separate images are created into D and bright field L, and these images are connected to a transmission eye meter 6, so that the boundary line between bright and dark can be read by the human eye. In such a refractive index hydrometer, the light source lamp 1 is lit continuously from the start of measurement until the measurement of all samples is completed, so the temperature rise due to the heat generated by the light source lamp causes the temperature of each component inside the measurement system to increase over time. This will raise the temperature and affect the temperature of the measurement sample. Therefore, especially for substances such as urine whose specific gravity value has a large temperature characteristic, the measurement value changes depending on the measurement time, making it impossible to obtain a specific gravity value with good reproducibility. Furthermore, since the light source lamp is turned on even when it is not needed, such as during sample exchange, the power consumption is large, which is not economically preferable. Also, bright field L
In order to accurately know the position of the boundary between the dark field D and
It is necessary to make the light from the light source lamp 1 brighter and increase its energy, but if the light is made brighter, the heat generation from the light source will also increase, which will increase the temperature of the refracting prism and reduce the reproducibility of measured values. There is also the problem that it becomes worse.

The above-mentioned problem becomes a big problem especially when trying to downsize analytical instruments.

An object of the present invention is to provide a refractometer or a similar device that can automatically measure refractive index or specific gravity and can prevent the brightness/darkness boundary image from being affected by temperature. be.

The present invention is provided with an automatic blinking means that operates a lamp drive circuit to light the lamp based on the input of an analysis start signal, and stops the operation of the lamp drive circuit when the number of scans of the photodetector reaches a predetermined number. Means is provided for applying a start pulse to the photodetector based on the input of the analysis start signal, and furthermore, preheating means is provided for constantly supplying a small current to the filament of the lamp while the lamp is turned off, and the photodetector is provided with a clock pulse. The scan is started by a start pulse, and the photodetector can output the bright field image area as a number of pulses, and based on this number of pulses, the refractive index or specific gravity of the sample can be determined. The above object has been achieved by configuring the system to obtain the following.

Embodiments of the present invention will be described in detail below with reference to the drawings. As shown in FIG. 2, this embodiment is an automatic refractive index hydrometer in which a scanning photodetector 9 such as a photodiode array is provided in place of the transmission scale meter of the conventional refractive index hydrometer. be. A video amplifier 10, a counter 11, a shift register 12, and a digital-to-analog converter (
(hereinafter referred to as a D/A converter) 13, an output amplifier 14, a clock generator 15, a preheating resistor 16,
A lamp drive circuit 17, a pulse generator 18, a flip-flop circuit 19, a scan end signal counter 20, and a start pulse generator 21 are added.
The other points are the same as those of the conventional example shown in FIG. 1, so the explanation will be omitted. The operation will be explained below. When the analysis start signal S enters the pulse generator 18, urine is simultaneously sucked into the sample cell 3 above the refracting prism 4. The output signal from the pulse generator 18 simultaneously clears the counter 11 and, after a short delay, also sets the flip-flop circuit 19. The set flip-flop circuit 19 provides a lamp lighting signal to the lamp drive circuit 17 to light the light source lamp 1. At the same time, the output signal from pulse generator 18 also provides a signal to start pulse generator 21 . After the lamp is turned on, the clock sent from the clock generator 15 is generated as one pulse by the start pulse generator 21 to create a start pulse. This start pulse is sent to the detector 9.
The detector 9 is constantly supplied with clock pulses from a clock generator 15, and starts scanning upon input of a start pulse. On the other hand, the light from the light source lamp 1 passes between the refraction prism 4 and the sample cell 3, is refracted at the center of the refraction prism 4, is focused by the objective lens 5, and forms a bright and dark image on the detector 9.

The detector 9 scanned by the start pulse sends the number of pulses within the bright field area imaged by the light source to the image amplifier 10. The amplified pulses are counted by a counter 11 and are counted by a shift register 12, for example 16 pulses.
The average of the measurements is taken, and the digital value is input to the D/A converter 13 and amplified by the output amplifier 14 to calculate the specific gravity value. Further, the detector 9 outputs a scan end signal every time one scan is completed, and the signal is input to the scan end signal counter 20. When the 16 scan end signals enter the scan end signal counter 20, a set signal is output from the scan end signal counter 20 to the flip-flop circuit 19, turning off the lamp drive circuit 17 and extinguishing the light source lamp 1.

Through the above operations, one specific gravity of urine, which is a measurement sample, is measured. When the light is off, through the preheating resistor 16,
A small current is always supplied to the filament of the light source lamp 1 to eliminate the starting current during lighting and to extend the life of the lamp. In a normal urine analyzer, the light source lamp is lit for about 3 seconds out of the 30 seconds required to analyze one sample, so the lamp lighting time during one measurement cycle is approximately 1/10 of the conventional time. , the temperature effect on urine is almost eliminated.

The time chart of this embodiment shown in FIG. 3 will be explained below.

In response to the sample suction start signal A, a lamp drive control signal B is sent to the lamp drive circuit 17 to turn on the lamp. For example, 16 measurements are performed while the lamp is on, and when 16 scan end signals C are counted, the light source lamp is turned off (N) and the measurement is completed. As the measurement data at this time, the average value of 16 measurements is output. D is the 16-time measurement signal, and E is the 16-time average output signal. Although the above embodiment is applied to a refractive index/hydrometer that calculates the specific gravity value from the refractive index of urine, the scope of application of the present invention is not limited to this, and the present invention can also be applied to a refractometer for liquid samples, for example. Can apply the invention.

As described above, according to the present invention, it is possible to automatically measure brightness and darkness images due to refracted light, and the temperature influence due to the lamp can be significantly reduced.

In other words, the operator can automatically obtain specific gravity or refractive index values that are not affected by temperature by simply pressing the start switch. Therefore, measurement values with excellent reproducibility can be obtained.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the configuration of a conventional refractive index and hydrometer, FIG. 2 is a diagram showing the configuration of an automatic refractive index and hydrometer according to an embodiment of the present invention, and FIG. 3 is a time chart showing the operation of the embodiment. 1... Light source lamp, 3... Sample cell,
4...Refraction prism, 9...Detector,
11...Counter, 13...Digital-analog converter, 15...Clock generator,
16... Preheating resistor, 17...
・Lamp drive circuit, 18...Pulse generator, 1
9...Flip-flop circuit, 20...
-Scan end signal counter, 21...Start pulse generator.

Claims (1)

[Claims] 1 Irradiate the sample cell on the refracting prism with lamp light,
In a refractometer or similar device that forms a bright and dark image of refracted light on a photodetector, a lamp drive circuit is operated to light the lamp based on the input of an analysis start signal, and the number of scans of the photodetector is controlled. automatic blinking means is provided for stopping the operation of the lamp driving circuit when the lamp reaches a predetermined number, and means is provided for giving a start pulse to the photodetector based on the input of the analysis start signal, and when the lamp is turned off, the lamp driving circuit is turned off. The photodetector is provided with a preheating means for constantly supplying a small current to the filament, the photodetector is provided with a clock pulse, and scanning is started by a start pulse, and the photodetector detects a bright field image. 1. A refractometer or similar device, characterized in that it is capable of outputting a region as a number of pulses, and is configured to determine the refractive index or specific gravity of a sample based on the number of pulses.