JPS61194318A - Proper sensitivity setting of supersonic wave level meter - Google Patents

Abstract

PURPOSE:To effect proper sensitivity setting of a supersonic wave level meter on the user side without using a synchroscope, by detecting sound wave in the specified range between emitting time of the sound wave and starting time of measurement, and indicating the result by comparing it with the identification value. CONSTITUTION:Emitting reverberating sound a inside an excessive sensitivity detecting gate 2 in front of a measuring gate 1 is detected for comparison with the identification value b and when the reverberating sound a exceeds the value b, excessive sensitivity indication is made with a lighted red lamp and on the other hand, when a reflected wave c exceeding the value b inside the measuring gate 1 is detected, the proper sensitivity is indicated with a lighted blue lamp. By said arrangement, as the proper sensitivity is indicated with a lighted blue lamp and an unlighted red lamp, a user has only to adjust the sensitivity properly for bringing said condition in existence.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for setting the appropriate sensitivity of an ultrasonic level meter.

[Prior Art] This type of ultrasonic level HA is used to measure the amount of vA in a container such as a powder or fluid. The time it takes to return
By measuring , the distance between the ultrasonic oscillator (a) and the surface of the contents is measured using the following formula, and the filling level of the contents is displayed.

To explain this measurement in more detail, as shown in Figure 3, since the emission reverberation (b) remains for t1 seconds after the sound wave is emitted, the measurement range (c) is the period after t2 seconds when this reverberation completely disappears, and this measurement range ( This is done by sensing reflected waves (e) that exceed a predetermined discrimination value (threshold level) (d) within (c). In other words, even if the emission reverberation (b) is detected before t2 seconds, no measurement is taken, and reflected waves below a predetermined level are precisely reflected waves (e) from the surface of the contents directly under the ultrasonic oscillator (a). Therefore, it is not measured, and the measurement is performed by sensing the reflected wave (E) that exceeds a predetermined level after t2 seconds. For example, if the reflected wave (e) exceeding the identification value is detected at the time of 12 seconds, the content filling level is 1.
00%, if it is seconds, it is 0%, and so on.

By the way, if the sensitivity of this ultrasonic level meter A to detect reflected waves (e) is too high, the launch reverberation (b) will be detected forever, and the launch reverberation (b) will be detected as shown by the imaginary line in Figure 3.
0) becomes elongated and enters the measurement range (c), and is detected at 12 seconds, which is the time when measurement begins.
Even if the contents are empty, the reading on ultrasonic level meter A is 100.
%, and - if the force sensitivity is low (that is, the level of the discrimination value (d) is high), the problem of the firing line W (b) will disappear, but this time the reflected wave (h) This makes it difficult to detect. Therefore, the sensitivity of the ultrasonic level meter must be set so that the reflected wave (e) stably exceeds the identification value (d) and the emitted reverberation (b) does not exceed the identification value (d) at the start of measurement. It is.

However, in the past, when setting this sensitivity, a synchronoscope was used to observe the reflected wave level of the sound wave and the sensitivity was set, but users of ultrasonic level meter A do not necessarily have a synchroscope on hand. In this case, it is difficult for the user to set the appropriate sensitivity.

[Problems to be Solved by the Invention] Therefore, the present invention aims to provide a method for setting the appropriate sensitivity of an ultrasonic level meter, which sets the appropriate sensitivity without using a synchroscope.

[Means for Solving the Problems] The method of the present invention detects a sound wave within a predetermined period of time after the sound wave is emitted and before the start of measurement and compares it with an identification value. When a reflected wave exceeding the discrimination value is detected after the start point, each display operation is performed separately, and the discrimination value is gradually varied, and the display operation by the reflected wave and the display by the emission reverberation are performed. The range between this and the operation is considered to be the appropriate sensitivity setting value range.

[Example of implementation] That is, as shown in Fig. 1, an over-sensitivity detection gate 2 is provided in front of the measurement gate 1, and the emission reverberation (b) inside the over-sensitivity detection gate 2 is detected to obtain the discrimination value (d). When the emission reverberation (b) exceeds the identification value (d), a red lamp (not shown) is lit to indicate oversensitivity, while the reflected wave (ho) exceeding the identification value (d) inside the measurement gate 1 is displayed. )
When detected, a blue lamp (not shown) is turned on to indicate appropriate sensitivity, and as the identification value (d) changes, the period from when the blue lamp is turned on until when the red lamp is turned on is set. is the appropriate sensitivity setting value range.

[Function] Since the method of the present invention is configured as described above, the launch reverberation (0
) is detected and compared in the sensitivity over detection gate 2, and when it exceeds the identification value (d), a red lamp lights up, indicating that the sensitivity is too high, and the sensitivity is lowered to eliminate the firing reverberation (0). If a sound wave is emitted and the blue lamp does not light up, you will know that the sensitivity is too low. In other words, the appropriate sensitivity is when the blue lamp is on and the red lamp is not, so the user can adjust the sensitivity as appropriate to achieve this state.

[Effects] As described above, according to the method of the present invention, the appropriate sensitivity setting of an ultrasonic level meter, which was conventionally done only by using a synchroscope and was therefore difficult for the user, can now be done without a synchroscope. This has the excellent effect of making it easier for the user to do so.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram of the method of the present invention, FIG. 2 is an explanatory diagram of measurement by an ultrasonic level meter, and FIG. 3 is an explanatory diagram of the measurement principle of the ultrasonic level meter. A...Ultrasonic level meter A...Ultrasonic oscillator Mouth...Emission reverberation C...Measurement range 2...Identification value E...Reflected wave 1...
Measurement gate 2...Oversensitivity detection gate Figure 1 Figure 2

Claims (1)

[Claims] 1. Detect the emission reverberation within a predetermined time period after the sound wave is emitted and before the measurement start point and compare it with the discrimination value, and if the emission reverberation exceeds the discrimination value and after the measurement start point. When a reflected wave exceeding the discrimination value is detected, each of the reflected waves is displayed separately, and the discrimination value is gradually varied, and a range between the display based on the reflected wave and the display based on the reflected reverberation is defined as an appropriate sensitivity setting value range. Appropriate sensitivity setting method 2 for an ultrasonic level meter, in which the ultrasonic level as set forth in claim 1 is displayed by lighting a blue lamp when the reflected wave is used, and lighting a red lamp when the emitted reverberation is used. How to set the appropriate sensitivity of the meter