JP4179508B2 - Dynamic characteristic measuring method and apparatus - Google Patents

Description

  The present invention relates to a method and apparatus for measuring the dynamic characteristics of a measuring instrument, and in particular, to simplify the dynamic characteristics of a measuring instrument in which dynamic characteristics such as a rise characteristic and a time constant are specified, such as a VU meter (Volume Unit meter) and a noise meter. The present invention relates to a method and an apparatus for measuring.

  Conventionally, for measuring dynamic characteristics, there has been a method in which a pure tone signal that lasts sufficiently longer than the rise time of the measuring instrument is input to the measuring instrument, and the movement of the indicated value is photographed with a high-speed camera.

  In addition, the measurement of the dynamic characteristics of the VU meter is a photoelectric pulse interval measurement method, that is, a light is applied to one point of the VU meter in advance, a start pulse is generated at the same time as a signal is input to the VU meter, and the needle emits light. A method of measuring the rising characteristic of the VU meter by detecting the moment of crossing the position with a light receiver and generating a stop pulse and measuring the time from the start pulse to the stop pulse (see “6 of Non-Patent Document 1”). However, devices such as a light source and a light receiver were necessary.

  In either method, a high-speed camera for photographing the movement of the needle or a light receiving device for detecting light is required, and dynamic characteristics cannot be measured using only acoustic equipment.

Japan Broadcasting Corporation, BTS 5703 VU total, established on January 20, 1955, revised on June 27, 1939

  Conventionally, video equipment or photodetectors for detecting the movement of the needle were required for measuring the dynamic characteristics. However, the object of the present invention is to easily measure the dynamic characteristics using only acoustic equipment. And providing a dynamic method and apparatus for measuring dynamic characteristics.

  The above and other objects and novel features of the present invention will be apparent from the description of this specification and the accompanying drawings.

  Of the inventions disclosed in this application, the outline of typical ones will be briefly described as follows.

  (1) A method for measuring the dynamic characteristics of a measuring instrument, in which a sine wave signal is measured for the rising characteristic of the measuring instrument for a duration ΔT1 required for measuring the rising characteristic of the measuring instrument. A first step that is generated at a reference level, and after the first step, a length sufficient to confirm that the movement of the indicator needle of the measuring instrument changes from a positive direction to a negative direction. A second step of stopping the generation of the sine wave signal for a duration ΔT2, and after the second step, a level variable sine wave signal is generated for a time sufficient to read an indication value of the measuring instrument. A dynamic characteristic measuring method for measuring a rising characteristic of the measuring instrument having a third step.

  (2) The dynamic characteristic measuring method according to (1) described above, wherein the level of the level-variable sine wave signal in the third step is changed, and the first to third steps are repeated. The level of the sine wave signal in the third step is adjusted so as to be equal to or substantially equal to the maximum value of the indicator needle of the measuring device in the first step.

  (3) A method for measuring dynamic characteristics of a measuring instrument, wherein a first step of generating a sine wave signal of a reference level for measuring a falling characteristic of the measuring instrument for a long time, and the first step A second step of stopping the generation of the sinusoidal signal for a duration ΔT1 required for measuring the falling characteristic of the measuring instrument, and after the second step, A third step of generating a sine wave signal at the reference level for a duration ΔT2 of a length sufficient to confirm that the movement of the indicator needle changes from a negative direction to a positive direction; And a fourth step of generating a level-variable sine wave signal for a time sufficient to read an indication value of the measuring instrument after the step 3, and a dynamic characteristic measuring method for measuring a falling characteristic of the measuring instrument. is there.

  (4) In the dynamic characteristic measuring method according to (3) described above, the level of the level-variable sine wave signal in the fourth step is changed, and the first to fourth steps are repeated. The level of the sine wave signal in the fourth step is adjusted so as to be equal to or substantially equal to the minimum value of the indicator needle of the measuring device in the second step.

  (5) A dynamic characteristic measuring apparatus for measuring a rising characteristic of a measuring instrument, a sine wave signal generating unit for generating a sine wave signal, a gate control unit for controlling output and stop of the sine wave signal, and the sine A level variable control unit for controlling the level of the wave signal, and a reference level for measuring the rising characteristic of the measuring instrument for a sine wave signal for a duration ΔT1 necessary for measuring the rising characteristic of the measuring instrument. After the generation of the sine wave signal, the generation of the sine wave signal is stopped for a duration ΔT2 long enough to confirm that the movement of the indicator needle of the measuring instrument changes from the positive direction to the negative direction. And a timing variable control unit for controlling the gate control unit and the level variable control unit so as to generate a level variable sine wave signal for a time sufficient to read an indication value of the measuring instrument.

  (6) A dynamic characteristic measuring apparatus for measuring a falling characteristic of a measuring instrument, a sine wave signal generating unit for generating a sine wave signal, a gate control unit for controlling output and stop of the sine wave signal, A level variable control unit for controlling the level of the sine wave signal and a reference level sine wave signal for measuring the falling characteristic of the measuring instrument are generated for a long time, and then the falling characteristic of the measuring instrument is measured. Long enough to stop the generation of the sinusoidal signal for the duration ΔT1 required for the time and then confirm that the movement of the indicator needle of the measuring instrument changes from a negative direction to a positive direction. The gate control unit generates a sine wave signal of the reference level for a duration of ΔT2, and then generates a sine wave signal of a variable level for a time sufficient to read an indication value of the measuring instrument. And said level A timing variable control unit that controls the variable control unit.

  (7) The dynamic characteristic measuring apparatus according to (5) or (6) described above, wherein the durations ΔT1 and ΔT2 are variable.

  (8) The dynamic characteristic measuring apparatus according to (5) or (6) described above, wherein the level of the level-variable sine wave signal is one selected from a plurality of fixed levels.

  According to the above-described means, in the measurement of the rising characteristic, the sine wave signal of the duration ΔT1 is output at the reference level as a short pure tone signal that lasts for the time to be measured from the state where the signal level is 0, and then continues. During the time ΔT2, the sine wave signal is stopped and a short silent period is inserted, and thereafter, the rising characteristic is measured by outputting the sine wave signal as a level variable pure tone signal for a long time.

  On the other hand, in the measurement of the falling characteristic, after outputting the sine wave signal as a reference level pure tone signal for a long time, the sine wave signal is stopped for a duration ΔT1, and a short silence period is inserted. After a sine wave signal having a duration ΔT1 is output as a pure tone signal having a short reference level, the falling characteristic is measured by outputting the sine wave signal as a variable level signal for a long time.

  The output from the dynamic characteristic measuring apparatus according to the present invention can be obtained by digital synthesis with a computer or the like. However, when the signals are synthesized in advance and it is difficult to change the duration or the level in real time, it is necessary to synthesize the signals with several types of durations and levels. In particular, when the level is varied, the measurement accuracy increases as the measurement is performed using the signal synthesized at the “best suitable level” shown in the “Embodiment of the Invention”.

  The effects obtained by the representative ones of the inventions disclosed in the present application will be briefly described as follows.

  According to the present invention, the dynamic characteristics of a measuring instrument that could not be measured without an imaging device or a photodetector can be measured only with an acoustic device.

  That is, it becomes easy to quantitatively clarify the measurement error of the VU level and the noise level caused by the variation in the dynamic characteristics of the VU meter and the sound level meter.

  Hereinafter, embodiments of the invention will be described in detail with reference to the drawings. Note that components having the same function are denoted by the same reference symbols throughout the drawings for describing the embodiment of the invention, and the repetitive description thereof is omitted.

  FIG. 1 is a diagram showing an example of the basic configuration of a dynamic characteristic measuring apparatus according to an embodiment of the present invention.

  As shown in FIG. 1, the dynamic characteristic measuring apparatus according to the present embodiment includes a sine wave signal generating unit 1 that generates a sine wave signal having a frequency based on a set value from an input unit (not shown), and a sine wave signal generating unit. 1, a gate control unit 2 that controls passage and blocking of the sine wave signal output from the level variable control unit 3, a level variable control unit 3 that varies the output level of the input sine wave signal, and a gate control unit 2 includes a timing variable control unit 4 that controls the passage and blocking timing of the sine wave signal in 2 and controls the output level in the level variable control unit 3. The dynamic characteristic measuring apparatus according to the present embodiment may be configured as an apparatus in which the sine wave signal generating unit 1, the gate control unit 2, the level variable control unit 3, and the timing variable control unit 4 are housed in one casing. Some or all of these are separate devices, and they may be connected by a cable or the like. In addition, the dynamic characteristic measuring apparatus of the present embodiment may be configured by a DSP (digital signal processor) or a CPU and a program stored in a storage device.

  The dynamic characteristic measuring apparatus according to the present embodiment generates timing pulses t1, t2, t3 and t4 with variable playback times from the timing variable control unit 4, and a sine wave signal generating unit according to the timing pulses t1, t2, t3 and t4. The signal from No. 1 is passed or blocked by the gate control unit 2 and the signal obtained by changing the level of each section by the level variable control unit 3 is used as a dynamic characteristic measurement signal.

  FIG. 2 shows an example of a “rise characteristic” measurement signal according to the present invention. The sine wave signal generator 1 generates a sine wave signal having a frequency suitable for the purpose. For example, when measuring the dynamic characteristics of a VU meter, about 1 kHz may be used. The frequency of the sine wave to be generated may be a frequency at which the signal rises in a rectangular wave sufficiently in a fraction of the rise time of the measuring instrument or a tenth of the time.

  At the time t1, the reference level L1 (for example, the rising characteristic of the VU meter is “when a 1 kHz sine wave signal indicating 0 VU is suddenly applied from 0 V, the time for the indicated value to reach 99% of 0 VU is 270 ms to 330 ms. The standard level L1 of the VU meter is 0 VU. If a signal having this standard level is input to the VU meter for a time sufficiently longer than the rise time, the VU meter indicates 0 VU. The signal is output at time t2, and after the signal is cut off at time t2, a signal having a level of L2 is output between time t3 and t4.

  By changing the timing pulses t1, t2, t3, and t4 in the timing variable control unit 4, the reference level signal duration ΔT1 (period of time t1 to t2) and signal cutoff time ΔT2 (time t2 to t2). (period of t3) and the duration ΔT3 of the signal of level L2 (period of time t3 to t4) can be changed.

  That is, the timing variable control unit 4 controls the gate control unit 2 to pass the sine wave signal input from the sine wave signal generation unit 1 to the level variable control unit 3 at time t1 and to control the level variable control unit 3 Then, by outputting the input sine wave signal level at level L1, a sine wave signal at level L1 is output as a measurement signal.

  Next, the timing variable control unit 4 controls the gate control unit 2 at time t2 to cut off the input sine wave signal, thereby stopping the output of the level L1 sine wave signal (measurement signal) at time t2. Let

  Next, the timing variable control unit 4 controls the gate control unit 2 at time t3 to pass the sine wave signal and also controls the level variable control unit 3 to output the level of the input sine wave signal at level L2. By doing so, a measurement signal of level L2 is output at time t3.

  Next, the timing variable control unit 4 controls the gate control unit 2 at time t4 to stop the output of the level L2 measurement signal at time t4 by blocking the input sine wave signal.

  As described above, the timing variable control unit 4 controls the gate control unit 2 and the level variable control unit 4 based on the timing pulses t1, t2, t3, and t4, so that the sine wave signal generated by the sine wave signal generation unit 1 is obtained. 2 is obtained and output to a measuring instrument (not shown).

  FIG. 3 shows how the indicated value of the measuring instrument changes when the measurement signal shown in FIG. 2 is input. Since the reference level signal is input at time t1, the instruction value increases, and at time t2, the signal becomes 0. Therefore, the instruction value starts to decrease. Further, since the signal of level L2 is input at time t3, the level changes to indicate the L2 level in a steady state, and the signal becomes 0 at time t4, so that the indicated value starts to decrease.

  The relationship between the duration ΔT1 and the indicated value at time t2 is the rising characteristic of the measuring instrument. At the time t2, the direction of movement of the indicator hand changes from positive to negative for a moment, so that it is possible to visually confirm the position indicated at the time t2. However, if you stare at this position, it is difficult to read the scale value. To read the scale value, you have to move your line of sight to the scale. As a result, the position of the peak becomes inconsistent, resulting in poor measurement accuracy. Therefore, following the cutoff time ΔT2, a level L2 signal is input, the level L2 is adjusted so that the indicated value becomes equal to the indicated value peak at the previous time t2, and the peak position is long ( ΔT3) so that it can be confirmed. That is, after setting the level L2 so as to instruct the instruction value at time t2 for a long time, the user can move the line of sight to the scale so that the instruction value can be read accurately.

  For example, in measuring the rising characteristics of the VU meter, the dynamic characteristics can be measured by changing ΔT1 in the range of about 0 ms to 330 ms or more and reading the peak value at each time t2. The length of ΔT2 may be a length at which it can be confirmed that the movement of the indicator needle changes from the positive direction to the negative direction at time t2, and is about 50 to 100 ms in the case of a VU meter. When ΔT2 is extremely close to 0, the peak value at time t2 may be influenced by the subsequent signal, and therefore it is not preferable to make it extremely close to 0. ΔT3 may be a time sufficient to read the indicated value, and may be about 1 second or longer. It is best to accurately match the level L2 with the peak value at time t2, but it is possible to accurately read the peak value at time t2 even if there is a slight deviation. However, when the levels are extremely different, the measurement accuracy is inferior.

  In actual measurement, it is preferable to read the peak value after the series of signals in FIG. 2 are repeatedly input to the measuring instrument and the level L2 is adjusted accurately. For example, when the measurement signal is repeatedly generated with the output pattern at times t1 to t4, the peak and level of the indicated value obtained from the sine wave signal at level L1 are increased by sequentially increasing or decreasing the level L3 for each repetition. The indicated value obtained by the L2 sine wave signal can be brought close to. As a result, the instruction value at the time t2 can be read with the duration ΔT3 which is a sufficient time for reading the instruction value, and the peak instruction value (maximum value of the indicator hand) can be read with high accuracy.

  FIG. 4 shows an example of a “falling characteristic” measurement signal according to the present invention. The sine wave signal generator 1 generates a sine wave signal having a frequency suitable for the purpose. For example, when measuring the dynamic characteristics of the VU meter, it may be about 1 kHz.

  The sine wave signal is output at a reference level L1 (for example, 0 VU in the case of a VU meter) for a sufficiently long time, cut off at time t1, and output at level L2 again at time t2, and then at time t3. A signal having a level L3 is outputted between t4 and t4, and a signal having a reference level L4 is outputted at time t4. By changing the timing pulses t1, t2, t3, and t4 by the timing variable control unit, the duration ΔT1 of the silent period, the duration ΔT2 of the level L2 signal, and the duration ΔT3 of the level L3 signal are changed. be able to.

  That is, similarly to the measurement of the rise characteristic described above, the timing variable control unit 4 controls the gate control unit 2 and the level variable control unit 4 based on the timing pulses t1, t2, t3, and t4, whereby a sine wave signal is obtained. The measurement signal shown in FIG. 4 is obtained from the sine wave signal generated by the generator 1.

  FIG. 5 shows how the indicated value of the measuring instrument changes when this measurement signal is input. The measuring instrument initially indicates the reference level, but the indicated value decreases because the signal is cut off at time t1. However, since the signal of level L2 is input at time t2, the indicated value starts to increase. Further, since the signal of level L3 is input at time t3, the level changes so as to indicate the level of L3 in a steady state, and since the signal of reference level is input at time t4, the measuring device indicates the reference level. It becomes like this. The level of L2 may be such that the direction of movement of the indicator hand changes from decreasing to increasing at time t2, but it may be usually the same as the reference level L1.

  The relationship between the duration ΔT1 and the indicated value at time t2 is the falling characteristic of the measuring instrument. At time t2, although the direction of the movement of the indicator hand changes from negative to positive for a moment, it is possible to visually confirm the position indicated at time t2. However, it is difficult to read the indicated value with high accuracy as in the case of measuring the rise characteristic. Therefore, a signal of level L3 is input, and the level L3 is adjusted so that the indicated value becomes equal to the peak of the drop at the previous time t2, and the position of the peak of the drop is confirmed over a long period (ΔT3). It can be so. That is, after setting the instruction value at time t2 to be instructed for a long time, the instruction value may be read accurately by moving the line of sight to the scale.

  For example, in measuring the fall characteristics of the VU meter, the dynamic characteristics can be measured by changing ΔT1 in the range of about 0 ms to 330 ms or more and reading the peak value of the drop at each time t2. The length of ΔT2 may be a length at which it can be confirmed that the direction of movement of the indicator hand changes from negative to positive at time t2, and is about 50 to 100 ms in the case of a VU meter. When ΔT2 is extremely close to 0, the peak value of the drop at time t2 may be affected by the subsequent signal, and therefore it is not preferable to make it extremely close to 0. ΔT3 may be a time sufficient to read the indicated value, and may be about 1 second or longer. It is best to accurately match the level L3 of the signal of the duration ΔT3 with the peak value at time t2, but it is possible to read the peak value at time t2 with high accuracy even if there is a slight deviation. However, when the levels are extremely different, the measurement accuracy is inferior.

  In actual measurement, it is preferable to read the peak value after the series of signals in FIG. 4 are repeatedly input to the measuring instrument and the level L3 is adjusted accurately. Also in this case, similarly to the above-described rising characteristic, for example, when the measurement signal is repeatedly generated with the output pattern at times t1 to t4, the value of the level L3 is sequentially decreased for each repetition, for example, 0 VU, In the case of −∞VU, the peak of the indicated value obtained by stopping the measurement signal can be made closer to the indicated value obtained by inputting the level L3 by sequentially increasing the value. As a result, the indicated value of the peak of the drop obtained by stopping the measurement signal for the duration ΔT1 can be read at the duration ΔT3 from time t3 to t4, which is a sufficient time for reading the indication value. The value (minimum value of the indicator needle) can be read with high accuracy.

  In the above description, the case where the rise characteristic and the fall characteristic of the VU meter are measured has been described. However, the measurement signal output from the level variable control unit 3 is converted into a pure tone by a speaker or the like and input to the sound level meter. Thus, a pure tone signal for measuring the rise characteristic and fall characteristic of the sound level meter is obtained as a measurement signal.

  As described above, the measurement signal generated and output by the dynamic characteristic measuring apparatus according to the present embodiment is input to the VU meter or the sound level meter to visually observe the fluctuation peak or the peak of the reading of the measuring instrument. Therefore, a high-speed camera or the like is not necessary for measuring the dynamic characteristics, and the dynamic characteristics can be easily measured using only the acoustic device.

  Since the dynamic characteristics of a measuring instrument such as a VU meter or a noise meter can be easily measured, measurement errors caused by variations in the dynamic characteristics of the measuring instrument can be objectively evaluated. It is also possible to exclude measuring instruments with poor dynamic characteristics.

  In the dynamic characteristic measuring apparatus of the present embodiment, the signal output level within the duration ΔT3 is constant at the level L2. For example, the inspector can vary the level L2 by the volume or the like within the duration ΔT3. By doing so, the instruction value of the duration ΔT3 may be matched with the instruction value of the time t2.

  The invention made by the present inventor has been specifically described based on the embodiment of the invention, but the invention is not limited to the embodiment of the invention and does not depart from the gist of the invention. Of course, various changes can be made.

It is a figure which shows the example of a fundamental structure of the dynamic characteristic measuring apparatus which is one embodiment of this invention. It is a figure which shows the example of the signal for "rise characteristic" measurement by this invention. It is a figure which shows the example of the change of the instruction | indication value of the measuring device by the signal for a rise characteristic measurement shown in FIG. It is a figure which shows the example of the "fall characteristic" measurement signal by this invention. It is a figure which shows the example of the change of the instruction | indication value of a measuring device by the signal for a fall characteristic measurement shown in FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Sine wave signal generation part 2 ... Gate control part 3 ... Level variable control part 4 ... Timing variable control part t1, t2, t3, t4 ... Control time (DELTA) T1, (DELTA) T2, (DELTA) T3 ... Duration L1, L2, L3 , L4: Signal level

Claims (8)

A method for measuring the dynamic characteristics of a measuring instrument,
Generating a sinusoidal signal at a reference level for measuring the rising characteristic of the measuring instrument for a duration ΔT1 required to measure the rising characteristic of the measuring instrument;
After the first step, a sine wave signal is generated for a duration ΔT2 that is long enough to confirm that the movement of the indicator needle of the measuring instrument changes from a positive direction to a negative direction. A second step of stopping;
After the second step, a third step of generating a level-variable sine wave signal for a time sufficient to read the reading of the measuring instrument;
A dynamic characteristic measuring method for measuring a rising characteristic of the measuring instrument. The dynamic characteristic measuring method according to claim 1,
The level of the level-variable sine wave signal in the third step is changed, the first to third steps are repeated, and is equal to or approximately equal to the maximum value of the indicator needle of the measuring device in the first step. A dynamic characteristic measuring method for adjusting a level of a sine wave signal in the third step so as to be equal. A method for measuring the dynamic characteristics of a measuring instrument,
A first step of generating a reference level sine wave signal for measuring a falling characteristic of the measuring instrument for a long time;
After the first step, a second step of stopping the generation of the sinusoidal signal for a duration ΔT1 required to measure the falling characteristic of the measuring instrument;
After the second step, the sine wave of the reference level for a duration ΔT2 long enough to confirm that the movement of the indicator needle of the measuring instrument changes from a negative direction to a positive direction. A third step of generating a signal;
After the third step, a fourth step of generating a level-variable sine wave signal for a time sufficient to read the indicator value of the measuring device;
A dynamic characteristic measuring method for measuring a falling characteristic of the measuring instrument. The dynamic characteristic measuring method according to claim 3,
The level of the level-variable sine wave signal in the fourth step is changed, the first to fourth steps are repeated, and is equal to or approximately equal to the minimum value of the indicator needle of the measuring device in the second step. A dynamic characteristic measuring method for adjusting a level of a sine wave signal in the fourth step so as to be equal. A dynamic characteristic measuring device for measuring the rising characteristics of a measuring instrument,
A sine wave signal generator for generating a sine wave signal;
A gate control unit for controlling the output and stop of the sine wave signal;
A level variable control unit for controlling the level of the sine wave signal;
A sine wave signal is generated at a reference level for measuring the rising characteristic of the measuring instrument for a duration ΔT1 required to measure the rising characteristic of the measuring instrument, and then the indicator needle of the measuring instrument is The generation of the sine wave signal is stopped for a duration ΔT2 long enough to confirm that the movement changes from the positive direction to the negative direction. A timing variable control unit that controls the gate control unit and the level variable control unit so as to generate a sufficient time to read the indicated value of
A dynamic characteristic measuring apparatus comprising: A dynamic characteristic measuring device for measuring the falling characteristic of a measuring instrument,
A sine wave signal generator for generating a sine wave signal;
A gate control unit for controlling the output and stop of the sine wave signal;
A level variable control unit for controlling the level of the sine wave signal;
After generating a sine wave signal of a reference level for measuring the falling characteristic of the measuring instrument for a long time, the sine wave signal is generated for a duration ΔT1 necessary for measuring the falling characteristic of the measuring instrument. And then the sine wave of the reference level for a duration ΔT2 long enough to confirm that the movement of the indicator needle of the measuring instrument changes from a negative direction to a positive direction. A timing variable control unit that controls the gate control unit and the level variable control unit so as to generate a signal and then generate a level variable sine wave signal for a time sufficient to read the indication value of the measuring instrument; ,
A dynamic characteristic measuring apparatus comprising:   The dynamic characteristic measuring apparatus according to claim 5 or 6, wherein the durations ΔT1 and ΔT2 are variable. The dynamic characteristic measuring apparatus according to claim 5 or 6, wherein the level of the level-variable sine wave signal is one selected from a plurality of fixed levels.

Images