JP3523693B2 - Odor monitor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an odor monitor for detecting and displaying an environmental atmosphere (odor), and more particularly to an odor monitor for detecting not only a reducing atmosphere but also an oxidizing atmosphere in the environment. The present invention relates to a portable odor monitor capable of displaying.

[0002]

2. Description of the Related Art A conventional odor monitor for detecting and displaying an atmosphere in an environment displays only a positive maximum value or a minimum value when displaying a detected peak hold value.

[0003]

Therefore, in the case of the conventional odor monitor, in an environment where the value changes to the negative side, for example, in an environment where an oxidizing atmosphere exists,
This cannot be displayed, which is very inconvenient. Also, when trying to display both the positive and negative values, it is necessary to prepare two dedicated odor monitors, which is inconvenient and costly. However, there was a problem that it became expensive.

SUMMARY OF THE INVENTION The present invention has been made to solve such a problem, and an odor monitor capable of maintaining and displaying the peak value of not only a reducing atmosphere but also an oxidizing atmosphere in the environment is provided. The purpose is to get.

[0005]

SUMMARY OF THE INVENTION An odor monitor according to the present invention has a first odor sensor capable of detecting an atmosphere in a reducing and oxidizing environment, and a first odor sensor for storing information on characteristics of the odor sensor. Storage means and the above environment
Display means for displaying information indicating the presence of an atmosphere in the interior , and at least the odor sensor detects the reducing atmosphere based on the information in the first storage means and the detection output of the odor sensor.
If the air is detected, the value becomes positive and
Negative value when the sensor detects the above oxidizing atmosphere
While calculating the information indicating the presence of the atmosphere in the environment such that a control means for controlling the display means, at least
And a second storage means for storing the maximum value and the minimum value of information indicating the presence of the atmosphere of the computed environment by the control means, the control means on the basis of the information of the second storage means the environment the maximum value of information indicating the presence of the atmosphere in Oyo
And the minimum value can be displayed on the display means. It also indicates at least the presence of an atmosphere in the environment.
An operation means to instruct the storage of the maximum and minimum values of information
The second memory device based on the instruction of the operating means.
Information indicating the presence of the atmosphere in the environment stored in the column
The maximum and minimum values of the report are updated.
You. In addition, information indicating the presence of the above-mentioned atmosphere in the environment is
Oy index.

[0006]

[0007]

[0008]

According to the present invention, not only the positive maximum value and the minimum value but also the negative maximum value and the minimum value can be displayed on the display of the detection output of the odor sensor.
For example, even in an environment where an oxidizing atmosphere exists, the maximum value and the minimum value can be easily and accurately displayed.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing one embodiment of the present invention.
In the figure, 1 is a portable odor monitor, and 2 is an odor sensor made of, for example, a SnO ₂ semiconductor thin film for detecting an atmosphere in the environment such as a reducing atmosphere (gas) or an oxidizing atmosphere (gas). The odor sensor 2 has a resistance value that changes with respect to a reducing atmosphere and a resistance value that changes with respect to an oxidizing atmosphere in a direction opposite to that of a reducing atmosphere. scorching odor, i.e., the resistance value at high sensitivity to a reducing gas such as decreases, whereas, also detects a high sensitivity, for example, about 0.03ppm against ozone, oxidizing gases such as NO ₂ or the like, the The resistance value increases. Further, the odor sensor 2 standardizes its output, determines a reference gas or the like, and performs calibration.
Output of odor sensor 2 in nicotine 10ppm is +1.0
V, the output of the odor sensor 2 in 1 ppm of ozone is -1.0 V
It has been. 3 is a sensor interface connected to the odor sensor 2 and 4 is this sensor interface 3
Is a microprocessor unit (hereinafter, referred to as an MPU) that performs various arithmetic processing described later, to which a detection output of the odor sensor 2 is supplied.

The MPU 4 has an arithmetic section 41 as control means for performing arithmetic processing, an A / D conversion section 42 for A / D converting the detection output supplied from the odor sensor 2 via the sensor interface 3, and an arithmetic operation section. A ROM 43 which is connected to the unit 41 and pre-stores programs such as flowcharts shown in FIGS. 3 to 5 described below, a timer 44 connected to the arithmetic unit 41, and is interconnected to the arithmetic unit 41;
RA as a second storage means used in arithmetic processing
M45.

The RAM 45 stores, for example, as shown in FIG. 2, a work area 45a, a display area 45b for storing contents such as displays and alarms, and contents about the setting state of the odor monitor by key operation or the like. A setting area 45c;
A data area 45d for storing fixed data used for conversion of the odor index. As an example, the display area 4
The 5b, odor index N to be described later, the correction resistance value Z _nc in the environment, the peak hold lower-limit value PHN _L, the peak-hold upper limit PHN _H, display usage state to monitor STANDBY such as a bar graph contents, buzzer The ON / OFF / intermittent control, error contents and the display of the calculation method of the odor index such as AB CAL are stored. In the setting area 45c, the OFF / ON state of the absolute switching function and the auto calibration setting function are stored. 0N / 0FF status, peak hold value display function
Various setting states such as the 0FF / ON state and the OFF / ON state of the range switching function are stored.
Data similar to that of an EEPROM 7 described later is stored.

The MPU 4 also converts the information for monitoring the state of the power supply circuit, which will be described later, into an analog-to-digital (A / D) converter and supplies it to the arithmetic unit 41.
A D / A conversion unit 47 for converting the data from the A / A to an external device, and a serial / parallel conversion of the data from the arithmetic unit 41 to an external device such as a personal computer (not shown). A so-called universal asynchronous receiver / transformer (UART: universal asynchronous receiver / trans
serial-parallel and parallel-serial converter 48
And

Reference numeral 5 denotes a liquid crystal display (hereinafter, referred to as LCD) driver connected to the arithmetic section 41, and reference numeral 6 denotes an LCD as a display means driven by the LCD driver 5 to display various information. Reference numeral 7 denotes an EEPROM as first storage means interconnected with the arithmetic unit 41.
The EPROM 7 contains, for example, the saturation resistance value Z _m of the odor sensor 2 and the resistance value Z _ns 0 of the odor sensor 2 in a so-called clean air (standard state) in which there is no odor as fixed data required for calculating the odor index. , The resistance value Z _ns of the odor sensor 2 during the reference odor, the load resistance value R, the measured power supply voltage V, and the like, and other numerical data such as an alarm level value ARM.

Reference numeral 8 denotes an operation unit as operation means having keys corresponding to a plurality of functions connected to the operation unit 41. The operation unit 8 has at least, for example, power ON / OFF.
Use the ON / OFF key to turn on / off, the AUTO CAL key to turn on / off the auto calibration setting function, the P / V HOLD key to turn on / off the peak hold value display function, and the data selection Key to rotate the data setting function. Use the data setting function to select data (rotation to reduce the value). Press the key to turn the data setting function ON / OFF. ALARM SET key to turn on / off the absolute switching function. An AB CAL key for turning OFF, a RANGE key for turning ON / OFF the range switching function, and the like are provided. The AUTO CAL key is used for P / V HO during the data setting function.
The fixed data input function is activated by using the LD key together.

A buzzer 9 is connected to an arithmetic unit 41, which issues an alarm when the odor index exceeds a predetermined value or a power supply voltage falls below a predetermined value, and 10 is connected to a D / A conversion unit 47, An output buffer for outputting information relating to the odor index to the outside; 11 a power supply circuit; 12 a variable voltage regulator connected to the power supply circuit 11 for supplying a stabilized power supply voltage to each internal circuit; 13 a power supply Connected to the circuit 11,
This is a voltage regulator that supplies a stabilized voltage to a heater (not shown) of the odor sensor 2. The output buffer 1
0 and the D / A converter 47 constitute output means.

An output terminal 14 is connected to the serial-parallel and parallel-serial converter 48.
Is connected to a personal computer (not shown) via an RS232C level converter (not shown). Output terminals 15 and 16 are both connected to the output buffer 10, and the output terminals 15 and 16 are connected to the + side (reducing atmosphere), respectively.
And the odor index on the negative side (oxidizing atmosphere) are output.
Reference numeral 17 denotes an output terminal connected to the output side of the sensor interface 3. Raw data is supplied to the output terminal 17 directly from the odor sensor 2 via the sensor interface 3. It is to be noted that a data logger, a decoder and the like are connected to these output terminals 15 to 17 though not shown. Reference numeral 18 denotes an external commercial power supply (not shown) when the power supply circuit 11 operates as an AC adapter.
Power supply terminal connected to

Next, the operation will be described. First, the overall operation will be schematically described with reference to FIG. In the following description, the determination operation is entirely controlled by the arithmetic unit 41. When the power is turned on, first, in step S1, initialization such as reading data from the EEPROM 7 and storing it in the RAM 45 is performed as described later. Next, in step S2, as a warm-up, the process waits for a predetermined time, for example, three minutes until the odor sensor 2 is stabilized. Data can be set in the RAM 45 by key operation of the operation unit 8 even during the three minutes of standby. That is, in the three-minute standby (STANDBY) mode, in step S3,
It is determined whether or not there is a setting input, and if not, step S2
And waits for 3 minutes. If there is, in step S4,
A setting process for the RAM 45 as described later is performed.
During the standby mode, the character "STANDBY" is displayed on the LCD 6 in a predetermined area of the display screen, for example, an upper left area.

On the other hand, when three minutes have elapsed in step S2, the apparatus enters a ready mode, and the odor measurement starts. That is, first, in step S5, data on the on / off setting state of the peak hold value display function, the carburetion setting function, the absolute switching function, and the like are read from the RAM 45 as described later. Then, in step S6, the output of the odor sensor 2 is read and sampled via the A / D converter 42 and the sensor interface 3, and the necessary fixed data is EEPRO
M7, and as described later, step S7
In, the odor index is calculated. During the ready mode, the LCD 6 displays a character “READY” in a predetermined area of the display screen, for example, an upper left area, and a bar relating to the odor index displayed in the predetermined area of the display screen, for example, in the center. 0 for graph display and digital display
It is said.

The odor index is obtained by using a reference resistance at the intensity of odor as a reference to standardize a resistance that changes according to a state of a detection target, for example, odor pressure.
Using the above-mentioned fixed data stored in the ROM 7 and the output value (measured voltage) detected by the odor sensor 2, it is calculated as follows. First, the reference resistance r _ref is calculated by the following equation using fixed data.

R _ref = (Z _ns -Z _m ) (Z _ns 0 -Z _m ) / (Z _ns 0 -Z _ns ) (1)

[0021] Then, by converting the detected measurement voltage E by the odor sensor 2 to the resistance value by the following equation, to do this with the measured resistance value Z _n.

Z _n = R (VE) / E (2)

[0023] Then, in terms of the odor index N of the measured resistance value Z _n by the following equation.

[0024] _{N = r ref / r n =} r ref (Z0-Z n) / (Z n -Z m) (Z0-Z m) (3)

[0025] In the above (3), r _n is the resistance that varies with odor pressure, Z0 is the initial resistance of the odor sensor 2, as the Z0, as will be described later, as a state no smell When calculating the odor index based on the resistance value in the clean air, the resistance value Z _ns 0 in the clean air is used, and when calculating the odor index based on the resistance value of the atmosphere of the measurement environment, The middle correction resistance value Z _nc is used.

When the calculation of the odor index is completed in this way, in step S8, the calculated odor index is determined, and a necessary display, alarm, output to the outside, and the like are performed.
Then, the operation described above is repeated after a waiting time according to the value set in the timer 44. That is, in step S9, it is determined whether or not there is a setting input again.
In step S10, the same setting processing as in step S4 described above is performed, and the process returns to step S9 to repeat the same operation as described above. If not, in step S11, it is determined whether or not to enter the sampling operation. If not, the flow returns to step S9 to wait, and if it is necessary to enter, the flow returns to step S5 to repeat the above operation. This sampling operation is performed, for example, once per second. Thus, the entire operation is completed. As described above, in the present embodiment, the odor intensity in the environment is calculated as the odor index using the above formula, but the odor intensity based on the resistance change from the initial resistance of a general element is calculated. Alternatively, a method of performing the operation may be used.

Next, each step (routine) in FIG. 3 will be described in detail. First, the operation of “initial setting” in step S1 will be described with reference to FIG. After the power is turned on, in step S21, each part necessary for the operation of the MPU 4 is checked, and in step S22, the EEPRO
The data set in advance is read from M7.
Then, in step S23, it is determined whether or not the data has been normally read out. If the data can be normally read out, in step S24, the data is stored in the RAM.
45 is written to the data area 45d, and thereafter, during operation,
The data is read from the RAM 45. In the determination of the data in step S23, it is checked whether or not the numerical value of the data is within a predetermined range. If the numerical value is out of the predetermined range, it is determined that the data is erroneous.

On the other hand, if the data is not normally read in step S23, the process proceeds to step S25. As a case where the data is not read normally, for example,
There is a case where abnormal data is stored in the PROM 7 by mistake, or an error occurs at the time of reading data and the data cannot be read. Alternatively, EE
When data is read from the PROM 7, the data may not be set in the EEPROM 7 in the first place.
In particular, at the time of start-up immediately after manufacturing, naturally, no data is set. In such a case, since normal data cannot be read in step S23, in step S25, the LCD 6 is driven by the LCD driver 5 to display an error. For confirmation of these data, for example, the total value of the data to be read is stored in the EEPROM 7, and the total value of the read data is stored in the EEPROM 7.
The abnormality of the data may be determined by comparing the total value of the data.

Then, in step S26, the ROM
So-called default data is read from the memory 43, and the read default data is stored in the EEPROM 7 in step S27, and stored in the RAM 45 in step S28. Thereafter, an operation using the default data is performed as an odor monitor operation. . Note that the default data is read out collectively in the flowchart of FIG. 4, but it is checked whether or not there is a setting for each piece of data, and the default data is read out only for those that do not. Is also good. The default data is EEPR
Data corresponding to the data stored in the OM 7 is stored in the ROM 43 in advance as default data. The default data may be generated by software.

Performing such an initial setting operation as a process at power-on has the following advantages. In other words, when abnormal data is stored in the EEPROM 7 by mistake, the sensor characteristics are calibrated with such data, or the displayed odor index is converted to a correct value by calculation, resulting in an abnormal value. When the data is read from the EEPROM 7 and abnormal data cannot be obtained because the data cannot be obtained normally, the odor monitor also does not function. In such a case, the odor monitor is typically used as described above. By preliminarily setting characteristic data in the ROM 43 and performing processing using these data as default data when an abnormality occurs, the odor monitor can be operated normally, and the reliability of the apparatus can be improved.

Even when the above-mentioned characteristic data is not set in the EEPROM 7, the R
The odor index can be displayed by the data from the OM 43. Then, such default data is read from the ROM 43 and read from the EEPROM 7 or the RAM 4.
5 so that in the next cycle, R
The procedure for reading the default data from the OM 43 can be omitted.

Next, referring to FIG. 5 to FIG.
The operation of the "setting process" of 4 (S10) will be described.
First, the all calibration setting function will be described. The all-calibration setting function is a function of correcting the initial resistance value Z0 of the odor index. In step S31, it is determined whether the AUTO CAL key for turning on / off the auto-calibration setting function of the operation unit 8 has been pressed, and if it has been pressed, the setting area 45c of the RAM 45 is referred to in step S32. To determine whether the auto-calibration setting function is in the ON state or the OFF state.
"ON" is set in the setting area 45c of the RAM 45.

[0033] Then, in step S34, to correct the value of the measured resistance values Z _n, is set in the display area 45b of the RAM45 as the correction resistance value Z _nc in the environment, Step S35
, The time t of the timer 44 is set to 0. This correction is performed every predetermined time, for example, every 30 minutes. Step S
If the auto-calibration setting function is ON with reference to the setting area 45c of the RAM 45 at 32, the OF area is set to the setting area 45c of the RAM 45 in step S36.
Set F, correction of the measured resistance value Z _n is not performed. The current state at this time is displayed on a predetermined area of the display screen of the LCD 6, for example, at the upper right of the top, and the ON state is “AUTO CAL”, O
The FF status is displayed as "AUTO OFF".

On the other hand, if the AUTO CAL key has not been pressed in step S31, the operation
It is determined whether or not the AB CAL key for performing ON / OFF of the absolute switching function has been pressed, and if it has been pressed, in step S38, the absolute switching function is turned ON or OFF with reference to the setting area 45c of the RAM 45 in step S38.
It is determined whether the state is the F state, and if the state is the OFF state, step S3
In 9, ON is set in the setting area 45 c of the RAM 45, and if it is ON, RA is set in step S 40.
OFF is set in the setting area 45c of M45.

[0035] Function The absolute switching function, as described below, the initial resistance value Z0 the odor index was calculated as Z _{n s} 0, switches the display format of the display range and the peak-hold bar graph display screen LCD6 Thus, at the time of startup, it is in the OFF state. When the absolute switching function is changed from the OFF state to the ON state as described above, the state of the auto calibration setting function is saved, and the absolute switching function is set to the OFF state.

The absolute switching function is O
When the state is changed from the N state to the OFF state, the automatic calibration setting function state is returned to the saved state. That is, the auto-calibration setting function is linked to the absolute switching function, and when the absolute switching function is turned on, the auto-calibration setting function has priority. Therefore, in the setting processing routine, if there is any input operation, the setting processing operation is started.
If the input is the pressing of the AB CAL key, the ON / OFF state of the absolute switching function is switched, but if there is another input, other setting processing is performed. Here, as an example, a case where the setting processing of the auto calibration setting function is performed is shown.

On the other hand, if the AB CAL key has not been pressed in step S37, other setting processing is started. here,
For example, a case will be described in which a peak hold value display function for displaying the upper and lower limits of the odor index is entered.
In step S41, it is determined whether the P / V HOLD key for turning on / off the peak hold value display function of the operation unit 8 has been pressed. If the P / V HOLD key has been pressed, the setting area 45c of the RAM 45 is read in step S42. Determine whether the peak hall value display function is ON or OFF by referring to
If it is in the F state, in step S43, the RAM 45
Is set to ON in the setting area 45c.

In step S44, the currently detected odor index N is set to the peak hold upper limit value PHN.
Stored in the display area 45b of the RAM45 as _H, in step S45, stores the odor index N that are also currently detected in the display area 45b of the RAM45 as the peak hold lower-limit value PHN _L. Also, at step S42, R
If the peak hold value display function is ON with reference to the setting area 45c of the AM 45, in the step S46, OFF is set in the setting area 45c of the RAM 45.

As will be described later, this peak hold value is obtained by setting the initial value of the odor index acquired the next time the state changes from the OFF state to the ON state, and calculating the odor index until the state changes to the OFF state. It is compared and updated each time it is performed. Note that this peak hold value display function is turned off at the time of startup. If the peak hold value display function is ON, this peak hold value
D6 is displayed in a predetermined area, for example, a lower part of the display screen, and
Nothing is displayed in the F state. At this time, if the peak hold value is negative, a minus sign is attached before the numerical value, and if the peak hold value is positive, nothing is displayed.

On the other hand, if the P / V HOLD key has not been pressed in step S41, other setting processing such as a range switching function is started. This range switching function
Is a function for switching the full scale value of the bar graph displayed on the display screen. In step S47, it is determined whether or not the RANGE key for turning on / off the range switching function of the operation unit 8 has been pressed. If the RANGE key has been pressed, in step S48, the range switching is performed with reference to the setting area 45c of the RAM 45. It is determined whether the function is ON or OFF. If the function is ON, then at step S49, R
OFF is set in the setting area 45c of the AM 45, and if it is in the OFF state, in step S50, ON is set in the setting area 45c of the RAM 45. At this time, if the range switching function is ON, the bar graph scale value on the display screen of the LCD 6 displays, for example, 0 to 0.6.
In the FF state, 0 to 3 are displayed.
The range switching function is turned on at the time of activation.

In step S47, if the RANGE key has not been pressed, the program enters the data set function. This data set function is a function for setting various data necessary for the odor monitor. This data set function has two types, an alarm setting mode and a fixed data setting mode.
In the alarm setting mode, set the alarm level value of the alarm level alarm function. In the fixed data setting mode,
Set the fixed data used for calculating the odor index.

First, a case where the alarm level value of the alarm level alarm function is changed and set will be described with reference to FIG. In step S51, it is determined whether or not the ALARM SET key for turning on / off the data setting function of the operation unit 8 has been pressed, and if it has been pressed, in step S52,
The alarm level ARM among the fixed data stored in the EEPROM 7 is digitally displayed as "ARM" indicating the input of the alarm level value in a predetermined area, for example, a lower portion of the display screen of the LCD 6, in a digital manner. Further, an input cursor (_) indicating the current input position is pointed to the highest position of the integer part of the digitally displayed current value.

Then, in step S53, it is determined whether both the AUTO CAL key and the P / V HOLD key of the operation unit 8 are pressed, and if not, the process proceeds to step S5.
Proceed to 4. That is, here, only the alarm level value can be changed just after the ALARM SET key is pressed. Then, when changing the numerical value of the alarm level value ARM to be displayed, a cursor (_) is first displayed at the maximum digit portion of the numerical value displayed on the LCD 6, and only the numerical value at the position of the cursor can be changed. . To change the numerical value, use the △ and ▽ keys for selecting data on the operation unit 8.

That is, in step S54, P / V
If the HOLD key has not been pressed, the number of alarm level values displayed on the LCD 6 is incremented by one in step S55 by pressing the △ key in step S55, and similarly, by pressing the ▽ key in step S57. In step S58, the number of alarm level values displayed on the LCD 6 is decremented by one. As a result, the number of the digit at the cursor is scrolled between 0 and 9, and only the digit can be changed.

Then, the P / V HOLD key is used to move the digit of the numerical value. Therefore, when changing the number of each digit,
After changing the maximum digit using the △ and ▽ keys as described above, pressing the P / V HOLD key moves the cursor one digit. That is, in step S54, P / V HO
When the LD key is pressed and it is confirmed in step S59 that the digit is not the last digit, the input digit is moved in step S60. Then, similarly, the numerical value of the next digit is changed.

This is repeated until the last digit is changed to P /
When the V HOLD key is pressed, the cursor naturally returns to the maximum digit. At that time, that is, when it is confirmed in step S59 that the cursor is the last digit, in step S61, the alarm level value which is the changed data is displayed. ARM EEP
It is stored (written) in a predetermined area of the ROM 7. This data is stored in the EEPROM 7 simultaneously with the RAM 4
5 is stored in the data area 45d, but the data may be stored in the RAM 45 at the end of the entire setting process. Then, by pressing the ALARM SET key in step S62,
Although the setting processing routine is terminated, this operation does not write data regardless of the processing state. If the ALARM SET key is not pressed in step S51, other setting processing is performed in step S63.

When the fixed data in the EEPROM 7 is to be changed, after the ALARM SET key is depressed and the alarm level value ARM is displayed, the AU
By pressing the P / V HOLD key while pressing the TO CAL key, the display of all fixed data can be changed. next,
The case where the fixed data is changed and set will be described with reference to FIG. In step S53 (FIG. 6), the AUTO CAL
If it is confirmed that both the key and the P / V HOLD key have been pressed, the first fixed data among the fixed data stored in the EEPROM 7 is read out and displayed on the LCD 6 in step S64.

The fixed data stored in EEPROM7 is, as described above, the saturation resistance Z _m, the resistance value Z _ns 0 of dry air (STP), the resistance value Z _ns in the reference odor,
The load resistance value R, the measured power supply voltage V, and the like are stored, and the alarm level value ARM and the like are also stored as other numerical data. At first, for example, the saturation resistance value Z
_m is displayed, below, the resistance value Z _ns 0 of dry air (STP), the resistance value Z _ns in the reference odor, are displayed in order of the load resistance R and the measurement power supply voltage V. In that case, for example, saturation resistance value Z _m as an example are displayed as follows. Z _m □□□□□ 0 1 2 3 At that time, the cursor is displayed at the position of “Z” which is the first character in the display, and when the P / V HOLD key is pressed, the cursor moves to that position. It shifts one character at a time. And
When the numeral portion comes, the user can scroll between 0 and 9 by the △ key and the ▽ key in the same manner as in the case of changing the alarm level value, and the digit portion can be changed.

That is, in step S65, P / V
If the HOLD key has not been pressed, after confirming the pressing of the 桁 key in step S66, it is determined in step S67 whether the digit content is a character or a numeral. Saturation resistance value Z
The display number of _m is incremented by 1 and if it is a character,
In step S69, the fixed data before being stored in the EEPROM 7 is read and displayed on the LCD 6.
Similarly, after confirmation of depression of ▽ key at step S70, the in step S71, to determine digits contents letter or number, if number, display of the saturation resistance Z _m being displayed, in step S72 LCD 6 The number is decremented by one, and if it is a character, in step S73, EE
The next fixed data stored in the PROM 7 is read out and displayed on the LCD 6. As a result, the number of the digit at the cursor is scrolled between 0 and 9, and only the digit can be changed.

In order to move the digit of the numerical value,
Use the P / V HOLD key. Therefore, when changing the digit of each digit, the digit of the maximum digit is changed using the △ key and ▽ key as described above, and then the cursor is moved by one digit by pressing the P / V HOLD key. That is, in step S65, the P / V HOLD key is pressed, and in step S74,
If it is confirmed that it is not the last digit, the input digit is moved in step S75. Then, similarly, the numerical value of the next digit is changed.

This is repeated until the last digit is changed to P /
When the V HOLD key is pressed, the cursor naturally returns to the maximum digit. At that time, that is, when it is confirmed in step S74 that the cursor is the last digit, in step S76, the saturated resistance value which is the changed data is displayed. the Z _m EEPROM7
Is stored (written) in a predetermined area. In this case as well, the data is stored in the EEPROM simultaneously with the RAM 4.
5 is also performed on the data area 45d. When the ALARM SET key is pressed in step S77, the setting processing routine ends. However, this operation does not write data regardless of the processing state.

As a function of each of the △ key and 個 々 key, when both keys are operated in the above-mentioned display state, the display contents are changed. That is, as described above, when pressing the ▽ key in the character portion of the display contents vary view and has contents from the saturation resistance Z _m to the resistance value Z _ns 0 of subsequent drying in air (STP). Then, similarly to the above, the numerical value can be changed by the P / V HOLD key, the △ key, and the ▽ key, and the numerical value can be stored in the EEPROM 7.

The provision of such a data setting function has the following advantages. That is, the current EEPR
It is possible to display the data stored in the OM 7 and to update the numerical value of the data stored in the EEPROM 7 with the up / down keys, ie, the △ and ▽ keys, and the digit shift key, ie, the P / V HOLD key. Further, the displayed data can be scrolled by operating the up / down keys in the character portion, so that the device can be normally operated on site.

That is, if there is an odor sensor with data, the data can be directly input to the odor monitor, and the data of the odor sensor currently input can be read. Therefore, as in the prior art, it is not necessary to bring the odor sensor back to a factory or the like to replace the odor sensor, or to replace the odor sensor with a circuit in order to calibrate the odor sensor in a circuit. It is no longer necessary to attach and do
Work related to calibration and the like is simple, and monitoring can be performed efficiently.

Next, the operation of "data reading" in step S5 will be described with reference to FIG. In the entire flow, before the sampling of the output of the odor sensor 2, the setting for calculating the odor index as the setting state of the odor monitor is determined and set from the RAM 45 in this data reading routine. That is, before sampling the output of the odor sensor 2 and calculating the odor index, whether to use the resistance Z _ns 0 in dry air as the value of the initial resistance Z 0 used in the above equation (3), It is determined whether to use the middle correction resistance value _Znc .

Therefore, first, in step S81,
Reference is made to the setting area 45c of the RAM 45. Then, in a step S82, it is determined whether or not the AB CAL key for turning on / off the absolute switching function of the operation unit 8 is pressed, and if it is pressed, in a step S83,
The resistance value Z _ns 0 in the clean air is set to the initial resistance value Z 0 stored in the data area 45 d of the RAM 45. When using the resistance value Z _ns 0 in the clean air, the numerical value is
The odor index is calculated on the basis of the resistance value in dry air in a state where there is no odor. Therefore, it is effective when determining whether the atmosphere of the measurement environment is oxidizing or reducing, or when obtaining the absolute odor index of the measurement environment.

On the other hand, in step S82, the operation unit 8
If the AB CAL key for turning ON / OFF the absolute switching function of R is not pressed, at step S84, R
The initial resistance value Z0 display stored in the area 45b of the AM45 setting the correction resistance value Z _{n c} in the environment. When the resistance value _Znc of the correction resistance value in the environment is used, the odor index is calculated based on the resistance value of the atmosphere of the measurement environment. Correction resistance value Z in this environment
_{For nc} , the resistance value according to the atmosphere is set by the auto calibration setting function, and by setting the auto calibration setting function to the ON state, a predetermined period is set.
For example, it is updated every 30 minutes.

In this data reading routine, ON / OFF of the auto calibration setting function is set.
The state is not referred to because the absolute switching function has a higher priority than the auto calibration setting function. For the auto calibration setting function, the correction resistance value Z _nc in the environment is updated in the determination processing routine described later. It is enough if done.

The provision of the absolute switching function has the following advantages. That is,
Environmental changes including environmental gases other than those to be measured can be captured, and the influence of all other environmental gases can be measured using the output of the odor sensor in an atmosphere in clean air (standard state) as a reference value. Also, the sensor element used in the odor sensor generally has a positive output in a reducing atmosphere such as odor and a negative output in an oxidizing atmosphere. Can be displayed, and the absolute status of the environmental atmosphere can be displayed, and an inexpensive and versatile odor monitor can be obtained.

Next, with reference to FIG. 9, the operation of "smell index conversion" in step S7 will be described. The conversion of the odor index uses the above equations (1) to (3). Since (1) is a calculated value based on fixed data, it is calculated in the initial setting routine and stored in a predetermined position in the data area 45d of the RAM 45. Therefore, in step S91, according to the above equation (2),
Converting the accepted voltage E as the output of the odor sensor 2 to measure the resistance value Z _n. Then, in step S92, according to the above (3), to convert the measured resistance value Z _n to odor index N. In the above-described data reading routine, it is determined whether the numerical value used for the initial resistance value Z0 in equation (3) is the resistance value Z _ns 0 in clean air or the correction resistance value _Znc in the environment. However, the numerical value may be set when the odor index is converted in step S7.

Next, the operation of the "determination process" of step S8 will be described with reference to FIG. The routine of this determination process is a portion that performs processing using the odor index when the process of sampling the output of the odor sensor 2 and calculating the odor index is completed, and performs display, alarm, output, and the like. First, in step S101, the numerical value of the odor index N calculated in step S7 is stored in the display area 45b of the RAM 45, and in step S102, the bar contents relating to the numerical value of the odor index N are also stored in the RAM 45.
Is stored in the display area 45b, and the setting area 45c of the RAM 45 is referred to in step S103. And
In step S104, it is determined whether the P / V HOLD key for turning on / off the peak hold value display function of the operation unit 8 has been pressed. If the P / V HOLD key has been pressed, the display area 45b of the RAM 45 is displayed in step S105. The stored peak hold value PHN (peak hold lower limit PHN
_L and the peak hold upper limit value PHN _H ) are read.

Then, in step S106, the odor index N is compared with the peak hold upper limit value PHN _{H. If} the odor index N is lower than the peak hold upper limit value PHN _H , the odor index N and the peak hold lower limit value are further determined in step S107. comparing the value PHN _H, when the odor index N exceeds the peak hold lower-limit value PHN _L, that is, odor index N peak hold upper limit PH
When in the range of N _H peak hold lower-limit value PHN _L anything without updating, and stores the peak hold value PHN at that time in the display area 45b of the RAM 45.

[0063] On the other hand, when the odor index N exceeds the peak-hold upper limit PHN _H in step S106, also, when the odor index N is below the peak hold lower-limit value PHN _L in step S107, that is, the peak odor index N is hold upper when in the out-of-range value PHN _H peak hold lower-limit value PHN _L, respectively, at step S109 and S110, and updates the peak hold value, the updated peak hold value PHN R
It is stored in the display area 45b of the AM 45.

[0064] The peak hold upper limit PHN _H, the peak hold lower-limit value PHN _L, odor index N is not only a positive direction, since it is also detected negative direction, as the peak hold value PHN, even negative value It will be kept by comparison. Therefore, the maximum value can be maintained not only in the reducing atmosphere in the environment but also in the oxidizing atmosphere. Then, after performing other processing according to the setting state, a display on the LCD 6 and a warning by the buzzer 9 are performed according to the contents of the display area 45b of the RAM 45.

Here, as other processing, for example, in step S111, an alarm level alarm function is performed as alarm processing. This is a function for issuing an alarm by the buzzer 9 when the odor index N exceeds the set alarm level. At this time, at the time of alarm, the buzzer 9 sounds continuously. When the odor index N recovers below the alarm level, the buzzer 9 stops sounding. By pressing a specific key, for example, the ▽ key during the alarm, the sound of the buzzer 9 is stopped. If the state where the odor index N exceeds the alarm level continues thereafter, the sound of the buzzer 9 is not performed. Also, once the odor index N has recovered below the alarm level, if the odor index N exceeds the alarm level again, the buzzer 9 sounds.

In step S112, it is determined whether or not data logging is possible. That is, the data logging is performed from an external, for example, a personal computer to the serial-parallel and parallel-serial converter 48 connected to the output terminal 14. It is determined whether or not a flag indicating the request of (1) has been transmitted, and if there is a request for data logging, the process proceeds to step S113.
, A data logging process, that is, a data logging function is executed. This data logging function is a function to perform various settings required for data logging. Examples of the various settings include a data file name setting for setting a file name to be logged on a personal computer side, and a data request setting for an odor monitor. Setting which sets the cycle for performing the sampling. RS232 which requests the odor monitor for data for each cycle set by this sampling cycle setting.
There is a data file in which the odor index input by the C input or the RS232C input is written in a predetermined format, for example, a CV format.

In step S114, a battery check process, that is, a battery alarm function is executed. This battery alarm function monitors the output of the power supply circuit 11 via the A / D converter 46, for example, the battery voltage,
It is a function to issue an alarm when the value falls below a specified value. This function works in both the standby mode and the ready mode. At the time of alarm, L
In a predetermined area of the display screen of the CD 6, for example, "LAW BA
T. "is displayed, and the buzzer 9 sounds intermittently. A
When the battery voltage is restored to the specified value by the C adapter, the display of "LAW BAT." On the display screen of the LCD 6 is erased, and the buzzer 9 stops sounding. By pressing a specific key, for example, the ▽ key during the alarm, the sound of the buzzer 9 is stopped. If the state in which the battery voltage is lower than the specified value continues thereafter, the sound of the buzzer 9 is not performed. Also,
Once the battery voltage has been restored to the specified value and the battery voltage again drops, the buzzer 9 sounds.

Next, in step S115, the RAM
It is determined whether the auto-calibration setting function is in the ON state or the OFF state with reference to the setting area 45c of the 45.
If it is in the state, in step S116, the coefficient t related to the auto calibration is incremented by one. The coefficient t is incremented by one every time the odor index N is calculated from the position on the flow, and is basically one.
Since the calculation is performed every second, it is increased every other second. Then, in step S117, the coefficient t is compared with the predetermined number T. This predetermined number T is a numerical value for measuring, for example, 30 minutes, and since the coefficient t is every one second,
If T = 1800, 30 minutes will be measured. Therefore, if the coefficient t is not equal to the predetermined number T in step S117, that is, if 30 minutes have not elapsed,
In step S118, the display area 45 of the RAM 45
b, that is, the resistance value Zn measured 30 minutes ago is _expressed as L
Display on CD6.

If the coefficient t has become equal to the predetermined number T in step S117, that is, if it has reached 30 minutes, it is determined in step S119 whether the odor index N has exceeded a predetermined value, for example, 0.3. , The odor index N is 0.3
In the case of exceeding, the coefficient t is set to 0 in step S121, the process proceeds to step S118, and the same operation as described above is performed. That is, when detecting the odor is not rope updating the resistance value Z _n, and displays the resistance value Z _n which was measured 30 minutes before LCD 6.

[0070] On the other hand, in step S119, if the odor index N does not exceed a predetermined value, for example 0.3, that is, if not detected odor, in step S120, the measured resistance value Z _n at that time in the environment stored in the display area 45b of the RAM45 as the correction resistance value Z _nc.
Then, in step S121, the coefficient t is set to 0,
Proceeding to step S118, the display area 45 of the RAM 45
b, that is, the stored resistance value Zn is _displayed on the LCD.
6 is displayed. If the auto-calibration setting function is OFF in step S115 with reference to the setting area 45c of the RAM 45, step S118 is immediately performed.
To display the contents of the display area 45b of the RAM 45 on the LCD.
6 is displayed.

[0071] In this automatic calibration setting function, in the conventional gas sensor, etc., the change direction of the resistance value Z _n is fixed to the reduction side in the case of correction of the reference value, limit to a decrease side from the first reference value However, in this embodiment, since both the oxidizing and reducing atmospheres are measured, the reference value is corrected irrespective of the initial reference value and its changing direction. In this auto-calibration setting function, the reference value is corrected by the value at the end of the predetermined period.
In the case of every minute, a value representative of the data of 30 minutes, for example, an average value, a median value, or the lowest value among them may be used. A value of plus alpha or 80% may be used.

Having such a peak hold value display function has the following advantages. That is, not only the positive maximum value and the minimum value but also the negative maximum value and the minimum value can be displayed on the display of the peak hold value. In particular, for example, there is an oxidizing atmosphere that changes to the negative side. The peak hold value can be easily and accurately displayed even in a simple environment.

Further, the provision of the automatic calibration setting function has the following advantages. In other words, it is possible to automatically correct the odor index, and it is necessary to adjust the zero point with a volume to correct the odor sensor, or to put clean air and standard gas in the test box, as in the past. Therefore, correction can be performed simply, efficiently, and quickly, and the device can always be normally operated.

FIGS. 11 and 12 are flow charts showing another embodiment for updating the correction resistance value _Znc in the environment. FIG. 11 shows a case where the average value in a predetermined period is taken.
Is the latest value. First, in FIG. 11, in step S115, it is determined whether the auto calibration setting function is in the ON state or the OFF state with reference to the setting area 45c of the RAM 45.
At 116, the coefficient t associated with the auto calibration is incremented by one. Then, in step S122, the work area 45a of the RAM45 are obtained for each calculation of the odor index N the sum ShigumaZ _n measured resistance value Z _n
To be stored. Next, in step S117, the coefficient t is compared with the predetermined number T. If the coefficient t is not equal to the predetermined number T, that is, if 30 minutes have not elapsed, in step S118, the contents of the display area 45b of the RAM 45 are read. that, LCD 6 the resistance value Z _n which was measured 30 minutes before
To be displayed.

On the other hand, if the coefficient t has become equal to the predetermined number T in step S117, that is, if it has reached 30 minutes, it is determined in step S119 whether or not the odor index N has exceeded a predetermined value, for example, 0.3. , The odor index N is 0.3
In the case of exceeding, the coefficient t is set to 0 in step S121, the process proceeds to step S118, and the same operation as described above is performed. That is, when detecting the odor is not rope updating the resistance value Z _n, and displays the resistance value Z _n which was measured 30 minutes before LCD 6.

If the odor index N does not exceed a predetermined value, for example, 0.3 in step S119, that is, if no odor is detected, in step S123, when the update timing is reached, the measured resistance value Z _n calculates an average value ΣZ _n / t, replace its value to the correction resistance value Z _nc in the environment, the display region 45b of the value RAM45
To be stored. When the average value is obtained, each measured resistance value Z
_n may be stored in the work area 45a of the RAM 45, summed up at the time of updating, divided by the number, and the average value may be calculated. However, for this purpose, the capacity of the RAM 45 is required. Capacity is simplified.

When the processing in step S123 is completed, in step S121, the coefficient t is set to 0, and the flow advances to step S118 to display in the display area 45b of the RAM 45.
The contents of, i.e., now, the stored resistance value Z _n LCD 6
To be displayed. If the auto-calibration setting function is OFF with reference to the setting area 45c of the RAM 45 in step S115, the process immediately proceeds to step S118, and the contents of the display area 45b of the RAM 45 are displayed on the LCD 6.
To be displayed.

Next, in FIG. 12, in step S115, it is determined whether the auto calibration setting function is ON or OFF with reference to the setting area 45c of the RAM 45. The coefficient t related to the calibration is incremented by one. Then, in step S124, the difference value [Delta] Z (absolute value) between the corrected resistance value Z _nc measured resistance value Z _n and the environment for each calculation of the odor index N is calculated,
In step S125, the difference value ΔZ and the predetermined value Δ
Compare with Z _P. This predetermined value ΔZ _P is equal to the original measured resistance value Z.
_This is a value obtained by subtracting the correction resistance value _Znc in the environment from the value _Znp closest to _n .

[0079] If the [Delta] Z is greater than [Delta] Z _P in step S125, the in the case where it proceeds to step S117, the below in step S126, the Z _n as Z _np, also in the display area of RAM45 a [Delta] Z as [Delta] Z _P After storing, the process proceeds to step S117. Then, in step S117, the coefficient t is compared with the predetermined number T, and the coefficient t
Is not equal to the predetermined number T, that is, if 30 minutes have not elapsed, in step S118, the RAM 45
, That is, the resistance value Z _np measured 30 minutes ago is displayed on the LCD 6.

On the other hand, if the coefficient t has become equal to the predetermined number T in step S117, that is, if it has reached 30 minutes, it is determined in step S119 whether or not the odor index N has exceeded a predetermined value, for example, 0.3. , The odor index N is 0.3
In the case of exceeding, the coefficient t is set to 0 in step S121, the process proceeds to step S118, and the same operation as described above is performed. That is, when detecting the odor is not rope updating the resistance value Z _n, and displays the measured 30 minutes before the resistance value Z _np etc. LCD 6.

In step S119, if the odor index N does not exceed a predetermined value, for example, 0.3, that is, if no odor is detected, in step S127, Z _{np is set} to Z _{nc at} the time of updating. Also, ΔZ _P is replaced with the largest value (maximum value), for example, 9.9 in calculation, and the value is replaced with the display area 45 of the RAM 45.
b. As in the case of this case taking the average value, but each measured resistance value Z _n may determine the nearest value by comparing each value when updating stored in the work area 45a of the RAM 45, For this purpose, Since the capacity of the RAM 45 is required, comparing the difference value for each detection and storing only the closest value simplifies the capacity.

When the processing in step S127 is completed, in step S121, the coefficient t is set to 0, and the flow advances to step S118 to display in the display area 45b of the RAM 45.
Of the stored resistance value _Znc, etc.
6 is displayed. If the auto-calibration setting function is OFF in step S115 with reference to the setting area 45c of the RAM 45, step S118 is immediately performed.
To display the contents of the display area 45b of the RAM 45 on the LCD.
6 is displayed. In the above embodiment, the portable type odor monitor has been described. However, the present invention is not limited to this. For example, this odor monitor is provided in each room of a building, and the same operation as in FIG. 3 is performed. The odor index is individually calculated by using the system, the odor index of each room is individually collected, and the system having a receiving unit that performs the operation of the determination process (step S8) in FIG. The same effect is achieved.

[0083] As described above, according to the present invention, reducing
And a <br/> odor sensor capable of detecting the atmosphere in the oxidizing environment, and first storage means for storing information about the characteristics of the odor sensor, presence of the atmosphere of the environment
Display means for displaying the information indicating the stationary, on the basis of the detection output of information and odor sensor of the first storage means, <br/> the least, the odor sensor detects the atmosphere of the reducing
In this case, the value is on the positive side, and the odor sensor is
Control means for calculating information indicating the presence of an atmosphere in the environment such that the value becomes a negative value when an oxidizing atmosphere is detected , and controlling the display means; and at least the control means
Information indicating the presence of the atmosphere in the operation environment of the
And a second storage means for storing the maximum value and the minimum value, the control means on the basis of the information of the second storage means ring
Since to display the <br/> display means maximum value and minimum value of information indicating the presence of the atmosphere in the boundary, the display of the detection output of the odor sensor, the maximum positive value, not only the minimum , Negative maximum value and minimum value can be displayed. Especially in an environment where the value changes to the negative side, the maximum value and minimum value can be displayed easily and accurately. And
Particularly, there is an effect that it is useful for a portable type.

In addition, at least the presence of an atmosphere in the environment
An operation means for instructing storage of the maximum and minimum values of information indicating, <br/> information indicating the presence of the atmosphere in the environment which is stored in the second storage means based on an instruction of the operation means Since the maximum value and the minimum value are updated, there is an effect that a highly accurate monitor can be always performed. Also,
Since the information indicating the presence of the atmosphere in the environment is a smell index, even though such an oxidizing atmosphere is present,
There is an effect that the value can be easily grasped by a numerical value.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing one embodiment of an odor monitor according to the present invention.

FIG. 2 is a block diagram showing a main part of one embodiment of the odor monitor according to the present invention.

FIG. 3 is a flowchart for explaining the entire operation of FIG. 1;

FIG. 4 is a flowchart for providing a detailed description of an initial setting operation in FIG. 3;

FIG. 5 is a flowchart for providing a detailed description of the operation of a setting process in FIG. 3;

FIG. 6 is a flowchart for providing a detailed description of the operation of the setting process in FIG. 3;

FIG. 7 is a flowchart for providing a detailed description of the operation of the setting process in FIG. 3;

FIG. 8 is a flowchart for providing a detailed description of the data reading operation in FIG. 3;

FIG. 9 is a flowchart for providing a detailed description of an operation of converting an odor index in FIG. 3;

FIG. 10 is a flowchart for providing a detailed description of the operation of the determination process in FIG. 3;

FIG. 11 is a flowchart for providing a detailed description of the operation of another example of the auto calibration in FIG. 10;

FIG. 12 is a flowchart for providing a detailed description of the operation of still another example of the auto calibration in FIG. 10;

[Explanation of symbols]

1 Smell monitor 2 Odor sensor 4 Microprocessor unit (MPU) 41 Operation unit 45 RAM 6. Liquid crystal display 7 EEPROM 8 Operation unit 9 Buzzer 11 Power supply circuit

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) G01N 27/12 G01N 27/00

Claims (3)

(57) [Claims] 1. An odor sensor capable of detecting an atmosphere in a reducing and oxidizing environment, a first storage means for storing information on characteristics of the odor sensor, and the presence of the atmosphere in the environment Display means for displaying information indicating the following. Based on the information in the first storage means and the detection output of the odor sensor , at least the odor sensor detects
When the original atmosphere is detected, the value becomes a positive value.
When the odor sensor detects the oxidizing atmosphere
Calculates information indicating the presence of the atmosphere in the environment so as to be a negative value, and a control means for controlling the display means; and at least the presence of the atmosphere in the environment calculated by the control means. and a second storage means for storing the maximum value and the minimum value of the information that indicates, above the control means on the basis of the above information Symbol second storage means
An odor monitor characterized in that a maximum value and a minimum value of information indicating the presence of an atmosphere in the environment can be displayed on the display means. 2. At least the presence of an atmosphere in the environment is determined.
An operation means for instructing storage of the maximum and minimum values of information indicating, shows the presence of the atmosphere of the environment which is stored in said second storage means based on an instruction of the operation means
Claim 1, wherein the odor monitor so as to update the maximum value and the minimum value of the to information. 3. The information indicating the presence of an atmosphere in the environment is
3. The odor monitor according to claim 1, which is an odor index .