JPS5853748B2 - Digital Sosa Souchi - Google Patents

Description

[Detailed Description of the Invention] This invention enables high-speed scanning of a measured quantity, enables on-line processing after data storage, and enables scanning of an arbitrary range in an arbitrary order and an arbitrary number of times. The present invention relates to digital scanning devices.

In science and engineering, it is common to select two factors that have an important relationship, consider other factors constant, and examine the causal relationship between only those two factors.

When another factor y is related to factor X, we observe and experiment to see how the result y changes with changes in factor (this is called scanning), and by measuring the corresponding y, it is summarized in a two-dimensional graph with the factor X on the horizontal axis and the result y on the vertical axis, and by obtaining an analog display, the overall Understand the situation.

This state is shown in FIG.

However, in recent years, it has become common to perform data processing to obtain higher-order information from the results obtained, and since digital computers and the like are used as processors, factor X is scanned discontinuously at regular intervals. , Xl + X2+ x
31 yl corresponding to ``”'・, y2゜y31...
A method of finding... and processing it has come into use.

This is shown in FIG. Alternatively, a method may be used in which the factor X is continuously scanned, but the result y is sampled by an analog/digital computer at fixed time intervals and stored in the computer's memory.

However, in both of these methods, the factor Since there is no guarantee that the change will occur, there is a drawback that the correspondence between X and y is often insufficient.

This invention eliminates these drawbacks, reduces unnecessary information as much as possible, allows strict correspondence between X and y, and completely freely selects X, for example, Xl, X2.
*X3, change “” to X3 + X2 *x
1.・・・・Changes such as X2 + Xl +
The present invention provides a digital scanning device that can be freely adjusted to changes such as X3 + . . . .

This invention will be explained in detail below.

FIG. 3 is a block diagram for explaining the present invention in detail, where ■ is a measurement system, ■ is a digital scanning device according to the present invention, and ■ is a data processing system, which includes a data storage memory ■a, an arithmetic processing circuit mb, and It consists of an X-axis control circuit llIc.

■ indicates a processing result display system, and ■ indicates an operation control command board.

To explain its operation, first, when inputting the range, order, etc. of xi, as well as the number of repetitions of scanning from the operation control command board ■, the arithmetic processing circuit mb immediately makes a judgment based on the information, and the X-axis control circuit ■ c send commands to.

In accordance with the instruction, the X-axis control circuit mc sends a group of pulses containing necessary control information to the digital scanning device (2), and in accordance with the instruction, xi is transmitted to the measurement system.

xi follows the instructions from the operation control command board (■), and is completely optional.Xl t Xto sx3. Jump like... or xl.

X2, x3. . . . Execute scanning continuously.

At this time, yi corresponding to any xi is always read by the digital scanning device 2 in synchronization with the scanning of xi, and stored as a pair with (x is y t ) in the data storage memory ma.

The operation can be completed in a short time of about 1 to 2 seconds between roughly xi and then <xi+1.

These are the features of this invention. For example, when you want to find the maximum and minimum of change in Figures 1 and 2, only X5 and x7 are scanned and only the corresponding y5 and y7 are stored as a pair. However, other values of X are not scanned, thus significantly reducing the time required for scanning, preventing unnecessary information from being introduced, and improving the efficiency of the system.

If necessary, the results can be sent from the operation control command board V to the processing result display system (2) for display.

FIG. 4 shows an embodiment of the present invention, which is an example in which the present invention is applied to a digital mass scanning device.

The configuration and operation of FIG. 4 will be explained below.

Based on the command from the operation control command board (Fig. 3),
Control pulse from axis control circuit c is sawtooth wave generation circuit 1
When the signal is sent to , the digital mass scanning device (2) starts operating.

A sawtooth wave generation circuit 1 repeatedly generates a sawtooth wave with a predetermined peak voltage and time width, and outputs a synchronization pulse from a synchronization pulse generation circuit 2 that generates a synchronization pulse in synchronization with the falling edge of the sawtooth wave to an X gate 3. It is added to the X counter 4 via the X counter.

The X counter 4 counts the synchronization pulses, and a staircase wave proportional to this is obtained from the DA converter 5.

A combination of the sawtooth wave from the sawtooth wave generation circuit 1 and the staircase wave from the DA converter 5 is sent to the measurement system (2) as a mass scanning signal of the mass spectrometer.

The time chart in FIG. 5 shows these relationships, where Xi is the composite signal sent to measurement system I, a is the staircase wave from the DA converter 5, and b is the sawtooth wave from the sawtooth wave generation circuit 1. FIG.

Each sawtooth wave corresponds to each mass in the mass spectrum obtained by the mass spectrometer.

The waveform dividing circuit 6 divides the time axis of the sawtooth wave into regular intervals, and sends a series of start pulses C and stop pulses d to the synchronous gate switch I at predetermined times as shown in FIG.

As a result, the opening and closing of the X gate 8 is controlled, and the X gate 8 is opened for a predetermined time corresponding to each sawtooth wave, and the ion signal yi from the measurement system I is changed to the waveform g in Fig. 5. , voltage, and 8-wave number comparator 9 enter the Y counter 10 via the X gate 8 and are counted.

When the X gate 8 closes, the signal synchronous transmission pulse generation circuit 1
1 inputs the memory pulse e shown in FIG. 5 to the register memory 1.
2 and the register memory 13, whereby the mass number stored in the X counter 4 and the y counter 10 and the contents of the pulse signal after the y gate B of the ion signal yi corresponding thereto are stored in the register memory 12.13, respectively. is memorized.

Thereafter, the mass number i and the ion signal yi are sent as a pair to the data storage memory IIIa by a transmission command pulse f from the signal synchronous transmission pulse generation circuit 11 as shown in FIG.

The above operation makes it possible to scan a certain range in any predetermined order while maintaining reliable correspondence between the ion signal yi and the mass xi.

In the scanning of conventional mass spectrometers, the scanning and the acquisition of the ion signal yi are generally performed independently without being related to each other, so it is necessary to determine the mass number from, for example, changes in the ion signal over time. , processing was done using software methods that required a lot of memory, such as the center-of-gravity method.

Moreover, this centroid method requires the accumulation of a large amount of ion signals yi, which is often insufficient in terms of cost and operation.

However, the present invention not only solves these difficulties, but also sends a series of control pulses from the X-axis control circuit l[c to the upper and lower limit setting circuit 14 and the X gate 3, thereby generating an ion signal yi of any mass. This method minimizes the amount of memory required while increasing measurement efficiency by eliminating unnecessary information.

Further, according to the present invention, the cycle end pulse h corresponding to the end of a predetermined scan is set by the upper and lower limit setting circuit 1.
4 to 5 as shown in FIG. 5, the same scanning can be repeated an arbitrary number of times.

This allows ion signals of the same mass to be accumulated, making it possible to measure even weak ion signals with a high S/N ratio.

Figure 6, Tables 1 and 2 show the situation, and the sensitivity of the detector for detecting the ion signal yi is insufficient.
At a degree of 9A, a very small peak at 26 m/e (corresponding to the H20 water molecule ion) at 18 m/e (corresponding to the H20 water molecule ion) in a scan from 18 m/e to 26 m/e by the ordinary method without using this invention However, when the sensitivity of the detector is increased to 10-11 people, each peak at 20.24.25 m/e becomes visible.

The intensities of other peaks when 26 m/e is 100.00 are shown in Table 1.

If the sensitivity of the detector is maintained at 10-9 A and the digital scanning device according to the present invention is used to perform repeated scanning at an interval of 0.02 seconds per mass, the time taken when not according to the present invention is approximately the same. The results shown in Table 2 were obtained for the total scanning time.

The agreement between Tables 1 and 2 is very good, and the present invention can substantially increase the sensitivity by about 100 times.

This can be immediately applied to pollution analysis that requires high sensitivity.

In the experiment for obtaining Tables 1, 2, and 6, the sample pressure P was about 3 x 10-7 Torl' in total pressure, and the impact electron current Ie was 1.5 mA.

Detection sensitivity: 10-''A Scanning time per mass: 5 seconds Total scanning time from 19 to 26 m/e: 40 seconds or more As explained in detail, according to the present invention, the X-axis can be widely used in science and engineering spectroscopy. By changing the wavelength, electron energy, etc. to be scanned generally at equal intervals, it can be used for all measurements that measure the corresponding quantity, and it can also be used to repeatedly scan a certain range according to a predetermined order. Not only can it be used, but it can also be efficiently measured in pollution analysis by scanning only the characteristic absorption wavelengths of specific substances such as SO2, NO, NO2゜00, etc., such as infrared spectroscopy. be able to.

Therefore, the present invention can be applied not only to mass spectrometry, but also to a wide range of fields such as infrared spectroscopy, ultraviolet spectroscopy, and electronic spectroscopy, with remarkable effects.

[Brief explanation of drawings]

1 and 2 are diagrams for explaining an example of the relationship between factor FIG. 5 is a time chart for explaining the operation of the embodiment shown in FIG. These are mass spectra at three detection sensitivities from e18 to e26. In the figure, ■ is the measurement system, ■ is the digital scanning device, ■ is the data processing system, l1la is the data storage memory, mb is the arithmetic processing circuit, llIc is the X-axis control circuit, 1 is the sawtooth wave generation circuit, and 5 is the DA converter. , 12° and 13 are register memories.

Claims (1)

[Claims] 1. In a Dicle scanning device used in combination with a data processing system including a data storage memory, an arithmetic processing circuit, and an X-axis control circuit, means for generating a sawtooth wave corresponding to one unit of scanning emitted from the X-axis control circuit. a means for generating a staircase wave synchronized with the sawtooth wave; a means for combining the sawtooth wave and the staircase wave to obtain a scanning signal in the measurement system; 1. A digital scanning device comprising means for scanning an arbitrarily set range an arbitrarily set number of times according to an arbitrarily set order and storing the scanned data in the data storage memory.