JP3552353B2 - Gas concentration measurement device - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a gas concentration measuring device for measuring the concentration of a component to be measured, for example, NOx, CO, CO ₂ , O _2, etc. in a sample gas.
[0002]
[Prior art]
In a gas concentration measurement device such as a NOx meter, measurement data detected by a detection unit is output from a plurality of analog output terminals. The data output from each output terminal is required to be output as a plurality of output forms according to the application, such as recorder data, telemeter data, control data for combustion management, etc. The number to output, the moving average and other calculation conditions, and the output signal form (voltage, current, range, etc.) are different.
In addition, some users request that the output signal for the telemeter be held during calibration or maintenance without being transmitted to the telemeter.
[0003]
Many conventional gas concentration measurement apparatuses have a plurality of output terminals, but the form of a signal output from each output terminal is fixed, and is not a parameter according to a user's request. Therefore, a device that divides the output of one output terminal into a plurality of outputs, a calculator that performs a moving average and other calculations, and a device that provides an external signal when holding an output and holds the output signal are not required. By doing so, it responds to various requests from users.
[0004]
FIG. 1 shows such a conventional gas concentration measuring device. A device 6 for dividing an output signal into a recorder, a control, a telemeter, and the like at each output terminal 4 of the gas concentration measuring device 2 and a moving device. An arithmetic unit 8 for performing calculations such as averaging is externally provided. Among the devices for dividing the output, what is indicated as a symbol 6a is provided with a function capable of holding the divided output without transmitting it by an external hold command signal.
[0005]
[Problems to be solved by the invention]
As shown in FIG. 1, if the devices 6, 6a for dividing one output into a plurality of units and the arithmetic unit 8 are externally provided in accordance with the user's request, the production time is required for adding such devices. In addition, there is a problem that the whole measuring apparatus becomes complicated. Further, when it is desired to hold, it is necessary to provide a hold command signal from the outside, which is inconvenient in operation.
The external devices such as the devices 6 and 6a for dividing one external output into a plurality of units and the arithmetic unit 8 each have a unique output form. Cannot change the output parameters at any time.
[0006]
The present invention relates to an output terminal of a gas concentration measuring device, which eliminates the need for an external device, and can set the output form in accordance with a user's request, and can also change the parameters at any time, thereby improving productivity. The purpose of the present invention is to increase the simplicity of the apparatus and improve the operability.
[0007]
[Means for Solving the Problems]
FIG. 2 shows the present invention.
Detector 10 detects the measured component concentration of the sample gas, the output unit 12 includes a plurality of output terminals CH ₁ ~CHn. The storage unit 14 in correspondence with the output terminal CH ₁ ~CHn allocation and output signal form of the output terminal CH ₁ ~CHn measurement data measured by the detector 10 as a parameter and stores it. Storage unit 14 also optionally, calculation conditions, the timing of the limit values and output hold for alarm can also be stored in correspondence with the output terminal CH ₁ ~CHn as parameters. The input unit 16 is a keyboard or the like, and sets and changes parameters in the storage unit 14. Calculation and control unit 18 causes the output from the output terminals CH ₁ ~CHn according to the parameters stored measurement data detected by the detection unit 10 in the storage unit 14. The display unit 20 is a CRT or the like, which is used when setting parameters from the input unit 16 to the storage unit 14, and displays measurement data as needed.
[0008]
Prior to the measurement, in accordance with the display of the display unit 20, it is set and stored in the storage unit 14 to input parameters for each output terminal CH ₁ ~CHn output unit 12 from the input unit 16.
At the time of measurement, the arithmetic and control unit 18 performs calculations such as concentration calculation and moving average on the signal detected by the detection unit 10 in accordance with the parameters stored in the storage unit 14, and outputs signals to the output terminals of the output unit 12. is output from the CH ₁ ~CHn.
[0009]
【Example】
In the embodiment, the description will be made on the assumption that the number of channels of the output terminal is nine.
FIG. 3 shows an example of an input screen displayed on the display unit 20, and is an input screen for setting parameters of the output terminals CH1 to CH9 in the storage unit 14. CH1 to CH9 represent measurement channel numbers and correspond to the terminal numbers of the analog output terminals.
[0010]
For setting of each item, the contents of the item can be changed by moving a cursor to a predetermined position and pressing a predetermined key, for example, a “SEL +” key or a “SEL−” key. By pressing a key, for example, the “ENTER” key, the selected content is stored in the memory area of the display unit 20 corresponding to the measurement channel number. When the contents stored in the display unit 20 are to be changed, the input screen is called from the menu screen, and changes are made in the same manner as when setting.
[0011]
In the screen of FIG. 3, a "measurement item" column is for setting a measurement target for a measurement channel. The measurement data set in the "measurement item" is analog-output from the output terminal of the channel.
Here, the moving average is used as the calculation. For each measurement item, it is set whether to output a moving average value or an instantaneous value. When a certain time is set in the "moving average" column, a moving average value for the set time is calculated and output, and an instantaneous value is output if **** is kept.
[0012]
The "Hold" column is used to set whether to hold the analog output signal during calibration or maintenance. If "None" is set, no hold is performed. If "Yes" is set, the calibration or maintenance mode is set. The analog output is held at the measured value just before the hold, and the hold is released when the calibration or maintenance mode ends. Although not displayed on the screen, when "0" is selected as "hold", the analog output holds the measured value as 0 when entering the calibration or maintenance mode, and is released when the calibration or maintenance mode ends.
[0013]
The "mA" column is used to set the output signal form at the time of measurement. 4 to 20 means that the range of 0 to range value is output at 4 to 20 mA. Other output signal forms can be selected.
The “Display” column is used to set whether to display the measured value on the monitor screen or not. If “Yes” is selected, the measured value is displayed on the monitor screen. If “No” is selected, the measured value is monitored. Does not appear on the screen.
[0014]
FIG. 4 shows a display screen for setting a function for monitoring a limit value of a measured value and notifying the limit value as an alarm. The "alarm 1 type" column and the "alarm 2 type" column are used to set whether the limit value is defined as an upper limit or a lower limit with respect to the measurement channel. It monitors and outputs an alarm when it becomes less than the limit value, and when "upper limit" is selected, it monitors the upper limit value and outputs an alarm when it exceeds the limit value. "Hysteresis" is for preventing the alarm from chattering when the measured density fluctuates near the alarm density, and can be set between 0 and 99%. Works effectively for all lower bounds.
[0015]
FIG. 5 shows a display screen for setting a limit value of the alarm screen. In the "measurement item" column, measurement items set using the display screen of FIG. 3 are displayed. The “Range” column displays the range value of the measurement item. For “Alarm 1” and “Alarm 2”, limit values for each range are set. For example, for channel CH1, “Alarm 1” is set as the lower limit in FIG. 4, so if “Alarm 1” is set to 5.0%, the measured value will be 5 ppm when the range is 100.0 ppm. Raises an alarm when it falls below. Also, since “Alarm 2” is set to the upper limit in FIG. 4, if “Alarm 2” is set to 60.0%, when the measured value exceeds 60 ppm when the range is 100.0 ppm, Output an alarm. The "limit" column is used to set whether or not to hold the analog output at the limit value set by the alarms 1 and 2 when the measured value exceeds the limit value. , And if "OFF" is set, the measured value is output as it is even if the measured value exceeds the limit value.
[0016]
【The invention's effect】
According to the present invention, it is not necessary to connect an external device for each user's request, and it is possible to set the form of the output terminal according to the user's request only by inputting and setting parameters from the input unit. Further, since the setting contents of the storage unit can be freely changed, when the user wants to change the output condition, the user can easily change the output condition. Since no external device is provided, the configuration of the device is simplified.
[Brief description of the drawings]
FIG. 1 is a block diagram showing a conventional gas concentration measuring device together with an external device.
FIG. 2 is a block diagram illustrating the present invention.
FIG. 3 is a diagram showing a display screen for setting parameters of output terminals in one embodiment.
FIG. 4 is a diagram showing a first display screen for setting alarm conditions in the embodiment.
FIG. 5 is a diagram showing a second display screen for setting alarm conditions in the embodiment.
[Explanation of symbols]
10 detection unit 12 output unit 14 storage unit 16 input unit 18 calculation / control unit 20 display unit

Claims (1)

A detection unit that detects the concentration of the component to be measured in the sample gas;
An output unit having a plurality of output terminals,
At least, a storage unit that stores the assignment of the measurement data measured by the detection unit to the output terminal and the output signal form in association with the output terminal as a parameter,
An input unit for setting and changing parameters in the storage unit;
A gas concentration measurement device, comprising: a calculation / control unit that outputs measurement data detected by a detection unit from each output terminal in accordance with parameters stored in a storage unit.

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