WO2002040989A1

WO2002040989A1 - Easy-to-use portable meter

Info

Publication number: WO2002040989A1
Application number: PCT/KR2001/001938
Authority: WO
Inventors: Tai-Jin Kim; Chang-Sik Sung
Original assignee: Biotel Co., Ltd.
Priority date: 2000-11-14
Filing date: 2001-11-14
Publication date: 2002-05-23
Also published as: AU2002224167A1

Abstract

An easy-to-use, portable meter for easily measuring dissolved oxygen, atmospheric oxygen, and temperature is provided. In particular, the meter is automatically initialized when power is turned on. When special initialization compensation is needed, a fine initialization process is performed by pressing a button for initialization (or a Calibration button). As the meter is operated in order of numbers assigned to buttons arranged on a front panel of the meter, power is applied, the meter is initialized, and dissolved gas, temperature, and atmospheric gas are easily measured. Also, the measure dissolved oxygen is displayed after temperature iscompensated for by a temperature compensation function. The scopes of measurement for measurement items are O-100°C for temperature, 0-100°C for temperature, 0-100% for atmospheric oxygen, and 0-50 mg/l for dissolved oxygen.

Description

EASY-TO-USE PORTABLE METER

Technical Field

The present invention relates to an easy-to-use, portable meter, and more particularly, to an easy-to-use, portable meter for measuring dissolved oxygen, atmospheric oxygen, and temperature by using the meter according to a series of numbers assigned to buttons, so that the meter can be simply turned on/off and initialized by manipulating the buttons, and dissolved oxygen, atmospheric oxygen, and temperature can be easily measured, and in particular, for the dissolved oxygen, accurate data can be obtained by automatically performing compensation with respect to temperature before displaying the data.

Background Art

In general, information on dissolved oxygen and atmospheric oxygen is very important in biology, medicine, and environmental science and engineering and is widely utilized in optimizing related processes.

A portable meter for measuring the concentration of oxygen is disclosed in

Korean Patent No. 0151940 (Application No. 1995-21158) by the subject applicant, entitled "Portable Dissolved Oxygen Measuring Apparatus". However, in the conventional portable dissolved oxygen meter, compensation for temperature is performed by manually rotating a switch and atmospheric oxygen and dissolved oxygen cannot be measured at the same time and initialization of the meter and a compensation method are difficult and inconvenient.

Disclosure of the Invention

To solve the above problems, it is an objective of the present invention to provide a portable meter for measuring an amount of each of dissolved oxygen, atmospheric oxygen, and temperature, which is easy-to-use because the meter is sequentially operated according to a series of numbers assigned to buttons and has an automatic compensation function with respect to temperature.

It is another objective of the present invention to provide a portable meter which can perform initialization concurrently with the application of power. Accordingly, to achieve the above objectives, there is provided a portable meter for measuring a concentration of a gas dissolved in a liquid, a concentration of a gas in a gas mixture, and temperature, the meter, which comprises a power portion for applying power, an input portion for receiving signals generated by sensors for sensing an amount of gas such as dissolved gas, atmospheric gas, and temperature, a selection button portion, including a predetermined number of buttons, for selecting a signal among the signals received by the input portion, a process portion for processing the signals selected by the selection button portion, and a display portion for displaying a quantity corresponding to the selected and processed signal It is preferable in the present invention that a series of numbers are assigned to the buttons of the selection button portion and, by pressing each button in order of increasing number, power is applied, the meter is initialized, and dissolved gas, temperature, and atmospheric gas are measured.

It is preferable in the present invention that the meter is automatically initialized when power is turned on, and when fine initialization is needed, a one-point method is used as a fine initialization process in which when a button for initialization is pressed in a normal state condition, that is, in normal air, the display portion indicates "Calibration", and then while numbers 0 through 9 are displayed and each number starting from 0 to 9 flickers, an initialization process is performed, and, if initialization is not properly performed after the fine initialization process is repeated three times, an error message is generated.

It is preferable in the present invention that the meter further comprises a temperature compensation means for compensating for effects on temperature on the measurement of the dissolved gas and/or the atmospheric gas in the dissolved gas sensor and/or atmospheric gas sensor by measuring a current temperature through the temperature sensor.

It is preferable in the present invention that a remaining amount of a battery is indicated on the display portion.

It is preferable in the present invention that power is automatically turned off when the meter is not manipulated in a predetermined way for a predetermined period.

It is preferable in the present invention that the input portion is connected to the sensors from which the input portion receives signals.

Brief Description of the Drawings

FIG. 1 is a perspective view showing an easy-to-use, portable meter for measuring dissolved oxygen, atmospheric oxygen, and temperature according to a preferred embodiment of the present invention;

FIG. 2 is a block diagram showing the structure of the portable meter of FIG. 1 ; and

FIGS. 3 through 7 are flow charts for explaining the operation when each of buttons on the portable meter of FIG. 1 is pressed.

Best mode for carrying out the Invention

The above objectives and merits of the present invention will be described in detail with reference to the attached drawings. First, the technical gist of the present invention is that a portable meter for easily measuring an amount of dissolved oxygen, atmospheric oxygen, and temperature includes a selection button portion 10 having selection buttons assigned with a series of numbers, a detection input portion 60, a process portion (not shown), and a display portion 30, as shown in FIG. 1 , so that the meter of the present invention can display a detected amount in a variety of ways, and perform functions such as automatic temperature compensation and one-point initialization. By the above technical structure, the objectives of the present invention can be easily achieved. Here, dissolved oxygen means oxygen dissolved in water and atmospheric oxygen means oxygen included in the air. Hereinafter, the structure and operation of the present invention will be described with reference to the attached drawings.

FIG. 1 shows a meter for measuring dissolved oxygen, atmospheric oxygen, and temperature according to a preferred embodiment of the present invention. FIG. 2 is a block diagram showing the internal structure of the meter. As shown in the drawings, the meter for measuring dissolved oxygen, atmospheric oxygen, and temperature according to the present invention includes a power portion 100, a detection portion (2, 4, and 6), a process portion 200, the selection button portion 10 (11 -15), the detection input portion 60, and the display portion 30.

The power portion 100 adopts a 9-Volt battery 55 and an adaptor 50 for supplying a constant voltage of 9 Volts for the convenience of use of the portable meter. Preferably, the battery 55 is a rechargeable battery. In the case of using a battery, a battery remaining amount check circuit 120 is operated at the application of power, to check the amount of the battery remaining and display the remaining amount on the display portion 30, so that the time for replacement or recharge of the battery can be determined. Here, the battery remaining amount is preferably displayed as a percentage on a battery remaining amount display 36 disposed at the lower portion of the display portion 30 of FIG. 2. Here, a push switch 130 may be used to operate the battery remaining amount check circuit 120. Alternatively, the battery remaining amount check circuit 120 may be formed to be automatically operated when power is applied to the meter. Also, when the adapter 50 is used, an AC-to-DC converting circuit 57 is provided so that power is applied to a power switch portion 140. When the first button 11 of the selection button portion 10 is pressed, the power switch portion 140 is operated under control of a microprocessor 20 so that power is supplied to a power bus 70 via a constant voltage circuit 110.

Also, when the portable meter for measuring dissolved oxygen, atmospheric oxygen, and temperature is not manipulated in a predetermined way for 5 minutes, the meter is automatically turned off to save power.

The detection potion (2, 4, and 6) includes sensors for measuring temperature, dissolved oxygen, and atmospheric oxygen, respectively, and is connected to the detection input portion 60 of the portable meter of the present invention. Alternatively, the detection potion (2, 4, and 6) may be integrally formed with the portable meter so that sensed signals are transmitted directly to the process portion 200.

The detection input portion 60 connected to a temperature detection sensor 2, a dissolved oxygen detection sensor 4, and an atmospheric oxygen detection sensor 6, measures the current temperature, a concentration of dissolved oxygen, and a concentration of atmospheric oxygen and provides the measured values to the process portion 200 of the meter of the present invention. The process portion 200 includes an amplifying portion, consisting of operational (OP) amplifiers 22, 24, and 26, for amplifying a sensing voltage, a selection portion 40, an A/D converting portion 45, and a microprocessor 20. A signal processed by the process portion 200 is displayed on the display portion 30. The selection button portion 10 includes five buttons 1 1 through 15, each being assigned with a number. The selection button portion 10 is easily operated by pressing the selection buttons in order and each selection button has a different function.

The power button 1 1 indicated by ON/OFF with number 1 on a front panel of the meter has a function of turning the push switch 130 in the power portion 100 on or off. That is, power is supplied by pressing the power button 1 1 once and the power is turned off by pressing the power button 1 1 again.

The button 12 indicated by CAL with number 2 on the front panel of the meter is used to perform initialization of the meter. When the CAL button 12 is pressed under a normal state condition (in the atmosphere), the display portion 30 displays

"Calibration" and initialization is performed. During initialization, the numbers 0 through 9 appear and each number flickers for one second on the display portion 30.

If the initialization is not completed while the above initialization is repeated three times, an error message is generated. Next, the button 13 indicated by DO mg/l with number 3 on the front panel of the meter may be pressed to display a dissolved oxygen detection result between 0 -

50 mg/l, preferably, 0 - 19.9 mg/l, measured by the dissolved oxygen sensor 4, on the display portion 30.

Next, the button 14 indicated by TEMP °C with number 4 on the front panel of the meter may be pressed to display a temperature in the range of 0 - 100°C, preferably, 0 - 50°C, measured by the temperature detection sensor 2 which is a thermistor, on the display portion 30.

Finally, the button 15 indicated by O₂% with number 5 on the front panel of the meter may be pressed to display a percentage concentration of atmospheric oxygen between 0 - 100%, preferably, 0 - 50%, measured by the atmospheric oxygen sensor 6, on the display portion 30.

Analog signals measured by the temperature detection sensor 2, the dissolved oxygen sensor 4, and the atmospheric oxygen sensor 6 are converted into digital signals at the process portion 200 and the converted digital signals are displayed on the display portion 30. Also, the display portion 30 includes battery remaining amount display 36 for displaying the amount of battery power remaining of the power portion so that the time to replace or recharge the battery can be determined.

The operation of the portable meter according to the present invention will now be described with reference to FIGS. 1 through 7.

First, the temperature detection sensor 2, the dissolved oxygen sensor 4, and the atmospheric oxygen sensor 6 are connected to the detection input portion 60. As shown in FIG. 3, when power is supplied by pressing the power button 11 (S302), the power and O₂% are checked (S304) and the results are displayed as initial values on the display portion 30 within a few seconds (S306). Thus, as soon as the power is turned on, brief initialization is performed. If the O₂% value displayed in S306 does not match 20.9% which is the oxygen concentration in a normal state (in normal air), as shown in FIG. 4, fine initialization is performed. In the case of fine initialization, by pressing the CAL button 12 in the normal state condition (in the atmosphere) (S402), "Calibration" is displayed on the display portion 30 to indicate an initialization process, and then numbers 0 through 9 are displayed and each number flickers for one second. While the numbers 0 through 9 are displayed, the initialization process is performed until a standard value becomes 20.9% or until the display of the numbers is finished (S404). The result of the initialization is displayed on the display portion 30 (S406). If the standard value does not becomes 20.9% after repeating the above initialization process three times, an error message is generated. The initialization process is performed again by pressing the CAL button 12.

The above-described present invention is designed such that fine initialization may be omitted since brief initialization is performed by checking O₂% when the power is applied. However, in another preferred embodiment of the present invention, fine initialization is performed, as if the initialization button is pressed, as soon as the power is turned on and the power and the battery remaining amount are checked. After the above process is completed, as shown in FIG. 5, the button 14 (TEMP °C, number 4) corresponding to the temperature detection sensor 2 connected to the input portion 60 is pressed (S502) so that temperature is measured (S504) and the result of the measurement is displayed on the display portion 30 (S506).

Next, as shown in FIG. 6, when the button 13 (DO mg/l, number 3) corresponding to the dissolved oxygen sensor 4 is pressed (S602), the amount of dissolved oxygen is detected by the dissolved oxygen sensor 4 (S604), temperature is measured (S606), and compensation for effects of temperature on the dissolved oxygen measurement is performed by the microprocessor 20 of the process portion 200 (S608). The resulting compensated dissolved oxygen is displayed on the display portion 30 (S610). Although a temperature compensation means is described in the drawings as software executed by the microprocessor 20, the temperature compensation means may consist of a thermistor of which a resistance value changes according to a measured temperature, a resistor for compensating for an error with respect to the thermistor, and a voltage dividing resistor. Also, the temperature compensation means may consist of a comparative amplification circuit for reducing an offset value, a resistor for compensating for temperature, and a variable resistor for compensating for an error due to the temperature of the circuitry, and a voltage dividing resistor. Since the configuration of the temperature compensation means is obvious to one skilled in the art, a detailed description will be omitted.

Next, as shown in FIG.7, when the button 15 (O₂%, number 5) corresponding to the atmospheric oxygen sensor 6 is pressed (S702), the atmospheric oxygen sensor 6 measures atmospheric oxygen (S704) and the result of the measurement is displayed on the display portion 30 (S610). Although no step of compensating for effects of temperature on the atmospheric oxygen measurement is shown in FIG. 7, a concentration of the atmospheric oxygen may be sensed and provided to the process portion 200 so that the measured concentration of the atmospheric oxygen is compensated according to the measured temperature and displayed on the display portion 30.

In the present invention, the power portion 100 includes a constant voltage circuit 110 so that power supplied to structural elements is stable regardless of a change in temperature.

Also, in the present invention, the temperature detection sensor 2 senses a current temperature and provides the sensed current temperature to the temperature compensation means of the process portion 200. When the button 14 of the selection button portion 10 for displaying temperature is pressed, the measured temperature is displayed on the display portion 30.

The A/D converting portion 45 of the process portion 200 of the present invention converts analog signals measured by the detection portion into digital signals which can be recognized by the microprocessor 20. Also, the microprocessor 20 of the process portion 200 controls each circuit in the meter and the taking of measurements in the present invention according to an action of each button.

As descried above, although the portable meter according to the present invention is described to measure dissolved oxygen, atmospheric oxygen, and temperature, since it is obvious to one skilled in the art that the present meter may be applied to a structure for measuring other gases, a description thereof will be omitted. Also, it is obvious that various modifications are possible within the scope of rights described in the following claims.

Industrial Applicability

As described above, the meter according to the present invention is used according to the numbers assigned to the buttons, and an automatic temperature compensation function is provided so that atmospheric oxygen and dissolved oxygen can be accurately measured and the meter is easy to use. Also, since initialization can be performed concurrently with the supply of power, the meter can be easily and conveniently used. Further, each of temperature, atmospheric oxygen, and dissolved oxygen can be measured.

Claims

What is claimed is:

1. A portable meter for measuring a concentration of a gas dissolved in a liquid, a concentration of a gas in a gas mixture, and temperature, the meter comprising: a power portion for applying power; an input portion for receiving signals generated by sensors for sensing an amount of gas such as dissolved gas, atmospheric gas, and temperature; a selection button portion, including a predetermined number of buttons, for selecting a signal among the signals received by the input portion; a process portion for processing the signals selected by the selection button portion; and a display portion for displaying a quantity corresponding to the selected and processed signal.

2. The meter as claimed in claim 1 , wherein a series of numbers are assigned to the buttons of the selection button portion and, by pressing each button in order of increasing number, power is applied, the meter is initialized, and dissolved gas, temperature, and atmospheric gas are measured.

3. The meter as claimed in claim 1 , wherein the meter is automatically initialized when power is turned on, and when fine initialization is needed, a one-point method is used as a fine initialization process in which when a button for initialization is pressed in a normal state condition, that is, in normal air, the display portion indicates "Calibration", and then while numbers 0 through 9 are displayed and each number starting from 0 to 9 flickers, an initialization process is performed, and, if initialization is not properly performed after the fine initialization process is repeated three times, an error message is generated.

4. The meter as claimed in claim 1 , further comprising a temperature compensation means for compensating for effects on temperature on the measurement of the dissolved gas and/or the atmospheric gas in the dissolved gas sensor and/or atmospheric gas sensor by measuring a current temperature through the temperature sensor.

5. The meter as claimed in claim 1 , wherein a remaining amount of a battery is indicated on the display portion.

6. The meter as claimed in claim 1 , wherein power is automatically turned off when the meter is not manipulated in a predetermined way for a predetermined period.

7. The meter as claimed in claim 1 , wherein the input portion is connected to the sensors from which the input portion receives signals.