JPS6360856B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a water quality meter for measuring turbidity, MLSS (activated sludge concentration), organic pollution, etc. used in water supply plants or sewage treatment plants.

FIG. 1 is a sectional view showing an example of a conventional optical turbidity meter, and FIG. 2 is a perspective view thereof. In the figure, 1 is the liquid to be measured, 2 is the light source, 3 is a lens for parallelizing the light beam ○a from the light source 2, and 4 is the transmitted light ○ out of the light beam ○a from the light source 2 that has passed through the liquid to be measured 1 5 is a second photocell that monitors the light intensity of the light source 2; 6 is the first photocell;
A computing unit 7 is a measuring tube which performs predetermined computing processing using the outputs X and Y of the second photocells 4 and 5 and sends out a turbidity proportional signal Z.

The operation of the turbidity meter configured as described above is as follows. The light beam ○a from the light source 2 placed at the focal position of the lens 3 becomes a parallel light beam ○b and the liquid to be measured 1
incident on . The light beams ○ and ○ are absorbed or scattered by the turbidity component of the liquid to be measured 1. The output X of the first photocell 4, which detects the ◯◯ of transmitted light, is expressed by the following equation (1) in accordance with Beer-Lambert's law.

X=Y exp [−εlx] …(1) Here, Y is the light intensity of light source 2, and ε is the measured liquid 1.
, l is the measurement length of the liquid to be measured 1, and x is the turbidity.

From equation (1), turbidity x is expressed by equation (2) below.

x=1/εl·lnY/X (2) Here, since the extinction coefficient ε and the measurement length l usually do not change, they can be set as a constant C. Therefore, the turbidity proportional value Z is determined from the output X of the first photocell 4 and the output Y of the second photocell that monitors the light intensity of the light source 2.
It can be found as shown in equation (3).

Z=C・lnY/X...(3) The calculator performs the calculation shown in equation (3) and calculates the turbidity proportional value Z.
Output. However, in this case, the measurement length l
Since it is fixed, the measurement dynamic range is narrow.

The present invention was made in order to solve the above-mentioned drawbacks, and an object of the present invention is to obtain a water quality meter whose measurement length can be varied.

The present invention was made to achieve the above object, and measures the turbidity, MLSS (activated sludge concentration), organic pollution, etc. of the object to be measured by the transmittance of light, ultrasonic waves, etc. passing through the object. In water quality instruments,
The present invention provides a water quality meter characterized in that a part of a measurement tube for sampling a liquid to be measured is configured in a bellows shape. Furthermore, the present invention provides a water quality instrument that measures the turbidity, MLSS (activated sludge concentration), organic pollution, etc. of a measured object based on the transmittance of light, ultrasonic waves, etc. passing through the measured object. A part of the measurement tube is made into a bellows shape, and as a means of adjusting the measurement length, the measurement length is controlled so that the transmitted signal from the object to be measured is always within a certain range, and the turbidity can be determined by referring to the measurement length value. The present invention provides a water quality meter characterized by outputting a proportional value. The present invention will be explained below using the drawings.

FIGS. 3a and 3b are cross-sectional views showing one embodiment of the present invention. In the figure, the structure from the liquid to be measured 1 to the second photocell 5 is the same as that described in the explanation of the conventional turbidity meter, but the measuring tube 7 has a bellows shape so that a part of the tube can freely expand and contract. The difference is that it is . Reference numeral 8 inputs the outputs X and Y of the first and second photocells 4 and 5 and the output L of the position detector 11 that generates an electrical output corresponding to the position of the light source head 9, performs predetermined arithmetic processing, and This is an arithmetic unit that generates a degree proportional value Z and a control signal for the motor 10. 9 is a light source 2, a lens 3, and a second photocell 5
This is a motor that moves the light source head 9 which is mounted on the head and is moved by the motor 10.

Next, the operation of the present invention configured as described above will be explained. As described in the description of the conventional turbidity meter, the light beam ○I from the light source 2 is converted into a parallel light beam ○B by the lens 3 and is irradiated onto the liquid to be measured 1 .

Furthermore, it is exactly the same that the output of the first photocell 4 that detects the amount of transmission of the luminous flux ○i is expressed by the relational expression shown in the above equation (1). In the turbidity meter according to the present invention, since a portion of the measuring tube 7 is bellows-shaped, the position of the light source head 9 can be freely moved in the longitudinal direction of the measuring tube 7. The position of the light source head 9 corresponds to the measurement length l and can be detected by the output L of the position detector 11. The arithmetic unit 8 inputs the outputs X and Y of the first and second photocells 4 and 5 and the above L, and calculates the following (4)
The turbidity proportional value Z is calculated and output using the formula.

Z=C/L·lnY/X (4) Further, the computing unit 8 monitors the first photocell output X, and controls the motor 10 to change the measurement length so as to obtain an appropriate output.

FIG. 3a shows a case where the turbidity of the liquid 1 to be measured is low, and the light source head 9 is moved back as the output X is large, so that the measurement length _l1 becomes longer. Further, FIG. 3b shows a case where the turbidity is high, and when the output X is small in the aforementioned _l1 , the output X is increased by advancing the light source head 9 and shortening the measurement length _l2 . In this way, the turbidity proportional value according to equation (4) can be output while the measurement length l is always optimally controlled.

The embodiments in which the present invention is applied to a turbidity meter have been described above, but the present invention may also be applied to water quality meters such as MLSS meters and organic turbidity meters, which have the effect of measuring length, and smoke concentration meters, or only optical type meters. It can also be applied to ultrasonic methods, etc. Furthermore, the light source head may be fixed and either the first photocell side or both photocells may be moved, and it goes without saying that the moving method is not limited to the motor.

As is clear from the above explanation, the water quality meter according to the present invention has great effects when implemented, such as expanding the dynamic range of measurement, improving the S/N of the detection signal, and obtaining stable output. It is.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing an example of a conventional turbidity meter, FIG. 2 is a perspective view showing the main parts thereof, and FIGS. 3a and 3b are sectional views showing an embodiment of the present invention. DESCRIPTION OF SYMBOLS 1...Liquid to be measured, 2...Light source, 4...First photocell, 5...Second photocell, 7...Measuring tube, 8...Calculator, 9...Light source head, 10...Motor, 11...Position detector.

Claims (1)

[Scope of Claims] 1. A water quality meter that measures the turbidity, MLSS (activated sludge concentration), organic pollution, etc. of a liquid to be measured based on the transmittance of a propagation signal such as light or ultrasonic waves passing through the liquid to be measured, A part between the generation source that generates the propagation signal of the measurement tube that samples the liquid to be measured and a receiving element that receives the propagation signal that has passed through the liquid to be measured, and a part between the generation source of the measurement tube and the reception element. A water quality meter characterized by having a bellows-shaped portion except for the gap. 2. The liquid to be measured is sampled with a water quality instrument that measures the turbidity, MLSS (activated sludge concentration), organic pollution, etc. of the liquid to be measured based on the transmittance of propagation signals such as light and ultrasonic waves passing through the liquid to be measured. a part of the measurement tube between the source that generates the propagation signal and a receiving element that receives the propagation signal that has passed through the liquid to be measured, and a part of the measurement tube other than the part between the generation source and the reception element. The measuring length is controlled so that the transmission signal of the liquid to be measured is always within a certain range, and the value of the measuring length is referred to as a means for adjusting the measuring length between the source and the receiving element. A water quality meter characterized by outputting a turbidity proportional value.