JP2653044B2 - Measurement output recording device - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a method for collecting data of an output of a measuring instrument over a long period of time, such as time recording by a spectrophotometer.

(B) Conventional technology Recorders are usually used to record measurement values over a long period of time.However, because a large amount of recording paper is consumed and the storage location of the records is also inconvenient, the recording range is limited, such as with an XY recorder or CRT display. In many cases, it is desired to record the data by a device which has been used. In this case, the measurement output is temporarily stored in a memory, and the content of the memory is read and recorded afterwards. For this reason, a large-capacity memory is required, and if the temporal change of the measurement output is to be accurately recorded, the sampling interval of the measurement output must be reduced, so that the required memory capacity is further increased. However, depending on the object to be measured, the temporal change of the measurement output is usually small and slow, and a large peak sometimes appears. For example, such a case is often observed when measuring the time change of the absorbance of a circulating sample using a spectrophotometer, and such an output state is exhibited even in a chromatographic output record or an atomic absorption spectrometric analysis. . In the measurement record in the case of such an output state, the period during which no peak appears is long, and it is useless to consume a large amount of memory capacity during that period.
If the sampling interval of the measurement output is increased, the recording accuracy of the peak decreases, and if the recording accuracy of the peak is increased, the utilization rate of the memory decreases, resulting in an expensive device.

C. Problems to be Solved by the Invention In view of the above-described situation, the present invention usually has a small temporal change, and a type of measurement output in which a peak sometimes appears. The purpose of the present invention is to enable measurement and recording of data, and to stably perform the operation.

D) Means for solving the problem Detect the temporal change rate of the measurement output, widen the sampling interval of the measurement output or the data storage interval to the memory while the temporal change rate is small, and The interval is narrowed, and automatic control is performed so as to maintain the narrow interval even near the peak apex while the measured output passes through the peak by peak detection.

E. As described above, when the temporal change rate of the measurement output is small, for example, the sampling interval is large, so that the memory capacity consumption is small, and while the time change rate is large, it is an important period for measurement.
In the meantime, the sampling interval is short and the accuracy of the measurement record does not decrease, so that the memory capacity can be effectively used, and the long-time measurement record can be performed with a small-capacity memory without lowering the accuracy. Although the temporal change rate of the measured output is small near the peak of the measured output, according to the present invention, a narrow sampling interval is maintained until the peak is passed, so that the rate of change of the falling side of the peak is not changed. It does not lead to a large portion, and the sampling interval changes near the peak apex, and the shape of the peak becomes unclear, and there is no flutter that frequently changes the sampling interval due to the influence of the nozzle.

F. Embodiment FIG. 1 is a flowchart of a measurement output sampling interval setting routine according to an embodiment of the present invention. In this embodiment, two types of measurement output sampling intervals, Po and Po / 10, are used. The difference between the previous and current sampling data is compared with a reference value. If so, set the sampling interval to 1/10 of Po. The operation will be described according to the flowchart of FIG. 1. According to whether the sampling interval is Po (wide) or not (a), when the sampling interval is Po, the operation proceeds to step (b), and the current sampling is performed. It is determined whether or not the difference between the data and the previous sampling data is larger than the first reference ΔA1. If the difference is smaller than ΔA1 (NO), the operation proceeds to step (c) and the next sampling pitch is set to Po. And
After one sampling operation, the next time starts again with the step (a). If the operation comes from step (a) to (b) and the determination in (b) is YES, that is, if the change rate is large, the operation goes to step (d) and the next sampling interval is set to P.
= Set to Po / 10, the next operation starts. At this time, in step (a), the sampling interval is not Po (N
From O), the operation proceeds to step (E) to determine whether the peak of the measured output has passed. The detection of the peak of the measurement output is performed by another program. If the peak has not yet passed (NO), the operation goes to (D), and the sampling interval P is subsequently set. Step (e) is YES
That is, when it is determined that the peak of the measured output has passed, the operation proceeds to step (f), and the measured value change amount is set to the second reference Δ
It is determined whether it is smaller than A2, and if smaller (YES), the operation proceeds to step (c), and the sampling interval is returned to Po. When the step (f) is NO, the operation proceeds to the step (d), and the sampling pitch remains narrow P.

Steps (e) and (f) will be described in the above operation. Normally, when the time change of the measurement output is small, the difference between the previous sampling data is monitored by monitoring the difference between the previous sampling data and the next sampling interval. I do not monitor. This is because the sampling interval is narrow, so that the influence of noise is large and the value of the difference fluctuates greatly. Therefore, it is separately confirmed that the peak of the measurement output has passed (step E), and the measurement value change amount Find out. Here, it is checked whether or not the difference between the measured data change amount and the current sampling data is smaller than the second reference ΔA2 by several points (for example, 10 points before). In this way, the influence of noise on the difference data can be reduced.However, if this method is used from the rising edge of the peak, the difference data may become smaller and smaller than the standard near the peak apex. Some points (for example, 10
Point) to confirm that it has passed.

FIG. 2 exemplifies a state of arrangement of sampling points by the above operation. The difference in the measured output between the sampling point a and the next b exceeds ΔA1, so that the sampling interval becomes narrower after b, and the number of points past the peak apex v and v ΔA2
When this operation is performed at each sampling point after the point v and comes to the point y, the difference between the measured output at the point x and a predetermined number of points before the point y is ΔA2 or less, and the sampling interval thereafter becomes Return to normal Po.

In the above embodiment, there are two types of sampling intervals.
It is also possible to use several stages according to the rate of change of the measurement output. In addition, if the data sampled in the above example is displayed on a CRT or XY plotter at a fixed pitch, the time axis will be markedly compressed, and the peaks will be displayed in an expanded form on the time axis for a long time in a narrow range. Minute data can be displayed, and important peaks are accurately displayed. When recording with an XY plotter, if the dot color is changed according to the sampling interval, the time-compressed part and the non-time-compressed part can be easily identified at a glance, and the dot of the mark will be displayed at the position where the sampling interval changes. By hitting, the time calculation of the entire display becomes easy.

Further, in the above embodiment, the sampling interval of the measurement output and the storage interval of the measurement output in the memory are the same, but the measurement output is always sampled at a short time interval, and the smoothing processing of the measurement output is performed. , Data may be extracted at appropriate intervals and transferred to a memory, time-differentiated on data that has been subjected to processing such as smoothing, and the size of the data extraction interval may be switched according to the magnitude of the differential value.

G Effect According to the present invention, it is clear from the above that according to the present invention, data where the change of the measurement output which is important for measurement is large is stored at a fine sampling interval, and other portions are stored at a coarse sampling interval. A long-term measurement data can be stored in a small-capacity memory without impairing the accuracy of the measurement record, and the compressed time axis is displayed easily and important parts are easily viewed.

[Brief description of the drawings]

FIG. 1 is a flowchart of a routine for setting a sampling interval in one embodiment of the present invention, and FIG. 2 is a graph showing a measurement output sampling state according to the above embodiment.

Claims (1)

(57) [Claims] 1. A means for monitoring a temporal change in the measurement output by comparing the previous sampling data and the current sampling data of the measurement output to store the measurement output in a memory, and a monitoring result of the monitoring means. With the means for selecting one of a plurality of stages of data storage intervals in the memory in accordance with the temporal change rate of the measurement output, and the means for storing the measurement output in the memory at the selected data storage interval, The peak of the measured output is detected by the monitoring means, and before the peak is detected, when the temporal change rate of the measured output becomes one value or more, the data storage interval is switched from large to small, and the sampling interval is set to the peak. After the peak is detected, after the peak is detected, the time change rate of the measurement output is obtained from the current time and the sampling data of a plurality of times before. Rate measurement output recording apparatus, wherein a comprises a control means for switching the large the data storage apart from small when it becomes less than a certain value.