JPS59120926A - Spectrophotometer - Google Patents

Abstract

PURPOSE:To make a display wavelength correct and to eliminate the possibility for reading erroneously the relation between a spectrum and the wavelength by having a counter which displays the real wavelength and a counter which displays the determined wavelength in a wavelength region relating to the calculation of an average method and displaying the contents of the counters as the display wavelengths for the entire spectrum in the wavelength range of the assigned spectrum. CONSTITUTION:A CPU calculates the measuring numbers A, B corresponding to the beginning point and end point of a spectrum (a) on a basis of the measured wavelength. The measuring number a=(A-n) corresponding to the start point for scanning is determined by subtracting (n) from the measuring number at the start point determined in (a), (b). The measuring number b=(B+n) corresponding to the end point of scanning is similarly determined by adding (n) to the measuring number at the end point determined in (a), (c). A spectroscope is driven and is moved to the wavelength position corresponding to the measuring number (a), (d), (e), and the measurement is started (f). When the spectroscope comes to the position corresponding to the measuring number (a+2n) (g), an average calculation is started (h), and the operation is repeated between (h) and (i) until the spectroscope arrives at the number (b).

Description

[Detailed description of the invention] The present invention relates to a wavelength display device for a spectrophotometer.

When measuring and displaying the spectrum of a sample substance with a spectrophotometer, the influence of noise can be reduced by averaging the spectrophotometer's measurement output using a moving average method while scanning the wavelength. I try to keep as much information as possible.

In this case, the measured display wavelength λ corresponding to the measured value obtained by the moving average is the center wavelength of this wavelength width, where Δλ is the data collection wavelength width of the moving average, and the spectrophotometer itself is It is located at a wavelength position of λ+, 乎λ/2, and there is a distance of Δλ/2 between the displayed wavelength and the actual wavelength of the spectrophotometer.
There is a difference of just that.

When Δλ is increased, this shift becomes impossible to ignore in terms of the spectrum.

In the present invention, when measuring a spectrum by wavelength scanning and displaying the spectrum by the moving average method, if the actual wavelength position of the spectrometer is displayed as it is, it will not match the wavelength (display wavelength) in the displayed spectrum. The purpose of this invention is to provide a spectral light transformation in which a display wavelength is calculated and displayed from the actual wavelength position.

Note that the present invention is applicable not only to the ordinary moving average method but also to the case of using the weighted average method.

The present invention provides a spectrophotometer that measures a spectrum by wavelength scanning and displays the spectrum using a moving average method or a weighted average method.
1, and a counter C2 that indicates a predetermined wavelength (not necessarily the center wavelength depending on the averaging method) in the wavelength range Δλ related to the calculation of the averaging method, and 2, when wavelength scanning is stopped. automatically selects the contents of counter C'- as the display wavelength, and during scanning, automatically selects the contents of counter C2 as the display wavelength, and selects the contents of counter C2 as the display wavelength for the entire spectrum from the start point to the end point of the wavelength range of the spectrum specified by the operator. The present invention provides a wavelength display device for a spectrophotometer that displays the contents of the counter C2 as a display wavelength.

According to the present invention, even if the moving average method or the like is employed, the displayed wavelength of the spectrum shows the correct wavelength, and there is no possibility of misreading the relationship between the spectrum and the wavelength when recording the spectrum. The present invention will be explained below with reference to Examples.

FIG. 1 shows an embodiment of the invention. 1 is a spectrophotometer, and the wavelength of the spectrometer is fed by a stepping motor. Reference numeral 2 denotes a control microcomputer which supplies pulses for driving a stepping motor to the spectrometer and divides the pulses by counters C1, C2. A spectral signal output from the spectrophotometer 1 is A/D converted and stored in the memory 3. A microcomputer (CPU) 2 reads the spectrum signal from the memory 3, calculates a moving average, and outputs the average value to a display device (for example, a recorder) 4 as a spectrum measurement value.

The CPU 2 outputs the count value of the counter C2 to the display j'iif:4 as the wavelength corresponding to the above spectrum measurement value.

The calculation of the moving average is performed from 1 to J as follows. Spectral measurements are performed at wavelength intervals of δλ. δλ corresponds to the wavelength feed of one pulse of the stepping motor. Since the spectrum measurements are performed intermittently in this manner, the spectrum measurements are numbered 1, 2, etc. from the beginning. The spectrum signals in the measurement of each of these numbers are stored at the address of the same number in the memory 3. The current measurement is m −
Assume that the progress is made in the 1-n dimension. The moving average is inheritance (2n+
One spectrum signal is taken and averaged.

In this case, the CPU starts from memory 3 at addresses m-n to m4.
Read and add the takes up to -n and divide by 2n+]. The value thus obtained in step 2 is the measured value of the spectrum l-/ for the wavelength λ corresponding to the m-th measurement number. In actual calculation, the moving average of the previous stage is m-n-1 to m-1.
Since the sum of the spectra signals up to -n -1 is calculated, the data of m-n-1 is subtracted, and m 4-11
All you have to do is add up the number data.

The calculation of the moving average is performed from the start of wavelength scanning to 2 n −,1−
This cannot be performed once the first measurement has been completed. The starting point of the displayed spectrum is the measurement number (n+1), and when the moving average for this is obtained, the spectrometer is ahead at the 2n111th measurement position. It is necessary that the contents of the size counters C1 and 02 differ by n.

The counter C2 initially stores a count value of -n, and in actual operation, the counters C1 and C2 count stepping motor drive pulses in exactly the same way.

FIG. 2 is a flowchart illustrating the outline of the operation of the CPU-U 2. The measurement numbers mentioned above start from number 1 and correspond to a certain wavelength. The operator sets the starting and ending wavelengths of the spectrum to be measured using the keyboard. Based on the set wavelength of the CPU, measurement numbers A and Bf corresponding to the start and end points of the spectrum appear (a).

Next, subtract n from the measurement number of the starting point obtained in (a) to determine the measurement number a==A-n corresponding to the scanning starting point (see).

In the same way, add n to the measurement number of the end point obtained in (a) to determine the measurement number b = B-1-n corresponding to the end point of the scan (
c). Next, drive the spectrometer at the wavelength position corresponding to measurement number a (2), (e), and start the measurement (f)
. When the spectrometer reaches the position corresponding to the measurement number a+2nKX'I (g), start averaging calculation (ch), and repeat steps from (h) to (su) until the spectrometer reaches the measurement number. ing. When reaching point b, the measurement operation ends. Counter C1, C
2 is a reversible counter whose counting contents always correspond to the wavelength position of the spectrometer.

The above-described embodiment implements a moving average method.

Even when performing the weighted average method, if weights are applied symmetrically on both sides of the center wavelength, processing can be performed in exactly the same way as on the upper side. When performing asymmetric weighting, the wavelength corresponding to the average value is no longer the center of the wavelength width related to the calculation, but in this case, the scanning starting point a =
A-n],,' t)=B-1-n2. This means that nl≠n2. Explanation still above - In the Ming Dynasty, counter C1,
C2 is assumed to be separate, but only counter C is used, and C1
It can also be replaced with 02 by performing an operation on the contents of .

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the configuration of an apparatus according to an embodiment of the present invention, and FIG. 2 is a flowchart showing an outline of the operation of the apparatus. Agent Patent Attorney Kosuke Tomo

Claims (2)

[Claims] (1) A counter C1 that measures the spectrum by wavelength scanning and displays the spectrum using a moving average method or a weighted average method, and shows the actual wavelength λ1 of the spectrometer.
and C1, it is characterized by having means for determining a predetermined wavelength within the wavelength range related to the above-mentioned average calculation, and displaying the wavelength indicated by the means as a wavelength value in a spectrum display. Spectrophotometer. (2) Calculate the scanning starting point wavelength of the average calculation for the starting point wavelength of the arbitrarily specified spectrum display range and the scanning starting point wavelength of the averaging calculation for the end point wavelength of the above spectrum display range, and scan these calculated wavelength ranges. A spectrophotometer according to claim 1, characterized in that: (μ bottom next page)