Method for detecting flushing noises of pedestal pan by sound power level parallelepiped measurement surface method

A technology of parallelepiped and sound power level, which is applied in the direction of measuring ultrasonic/sonic/infrasonic waves, measuring devices, instruments, etc., to achieve the effect of improving scientificity

Active Publication Date: 2019-05-14
李文杰
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AI-Extracted Technical Summary

Problems solved by technology

[0004] The technical problem to be solved in the present invention is to provide a slow time weighting characteristic "S" of the equivalent sound level of the weighted equivalent sound level of the sound level meter to the cumulative percentage sound power level L on the parallel...
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Method used

With reference to the installation instructions of the manufacturer, assemble the corresponding flushing device and water inlet pipe for the floor-standing ceramic toilet sample to be tested, and carry out the connection tightness test according to the provisions of Ar...
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Abstract

The invention relates to a method for detecting flushing noises of a floor type ceramic pedestal pan. The detection steps include sample installation and debugging, determination of a sound source reference body and a parallelepiped measurement surface, sound pressure level measurement, sound power level calculation and background noise, test environment and weather condition correction, and result evaluation. The method is specially characterized in that the flushing noises of the pedestal pan, represented by the cumulative percent sound power level LWA(50), on the parallelepiped measurementsurface are accurately and quantitatively detected by applying a slow time weighting characteristic "S" of the A weighting equivalent sound level of a sound level meter. It is stipulated that the A weighting cumulative percent time average sound pressure levels L'pAi(ST)(50) and LpAi(B)(50) of the flushing noises and background noises on the parallelepiped measurement surface are measured; the sound power level LWA(50) of the flushing noises in a normal flushing period is calculated; and meanwhile, a result evaluation basis is provided. The method fills the blank of the technical field of pedestal pan flushing noise detection; the scientificity of the method and the comparability of a result are achieved; and the technical support can be provided for ceramic enterprises to improve production processes and standardize market order.

Application Domain

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  • Method for detecting flushing noises of pedestal pan by sound power level parallelepiped measurement surface method
  • Method for detecting flushing noises of pedestal pan by sound power level parallelepiped measurement surface method
  • Method for detecting flushing noises of pedestal pan by sound power level parallelepiped measurement surface method

Examples

  • Experimental program(1)

Example Embodiment

[0131] The following describes the present invention in detail with reference to the accompanying drawings and preferred embodiments, so that the advantages and features of the present invention can be more easily understood by those skilled in the art, so as to define the protection scope of the present invention more clearly.
[0132] This embodiment takes the flushing noise detection of a floor-standing ceramic toilet product produced in Tangshan, Hebei, with an internal structure of a jet siphon type and a dual-stage nominal water consumption of 6L and 3L respectively, under the condition of full flushing water consumption as an example.
[0133] The specific detection method is carried out according to the following steps:
[0134] (1) Sample installation and commissioning
[0135] 1.1 Sample quantity and specifications
[0136] 3 samples of porcelain or stoneware floor-standing toilets of the same type, specification, and size produced by the same manufacturer and batch are used as a set. The internal structure can be flush or siphon type, using gravity such as flushing water tank Type flushing device (single flush or double flush).
[0137] 1.2 Sample installation
[0138] Equipped with flushing water tank and toilet water tank accessories that meet the requirements of rated water consumption, and equipped with a seat ring, cover plate and flange of suitable size (for a toilet sample with a rear drain type, a suitable flange should be used to drain it The way is adjusted from the rear row type to the bottom row type). In accordance with the standardized debugging procedures for the water tank test water supply system specified in Article 8.8.2.1 of GB 6952-2015, the water tank water supply system of the toilet sample to be tested should be debugged and meet the relevant requirements; the working water level of the flushing water tank can meet the normal flushing The process requires that the nominal water consumption is equal to the actual water consumption.
[0139] 1.3 Connection tightness test
[0140] Refer to the installation instructions of the manufacturer to assemble the corresponding flushing device and water inlet pipe for the floor-standing ceramic toilet sample to be tested, and conduct the connection tightness test in accordance with the provisions of 8.11 in GB 6952-2015, that is, the test water pressure condition of 0.1MPa Keep it continuously for 15 minutes, and there should be no leakage in the connecting pipeline to ensure that the toilet and flushing device have good overall sealing.
[0141] 1.4 Sample positioning
[0142] 1.4.1 For floor-standing ceramic toilet samples that are not close to any wall during installation, if the test is performed in an acoustic environment similar to a free field above the reflective surface of the semi-anechoic chamber, the sample to be tested can be directly placed in the center of the ground and ensured The flushing function is normal. If the test is performed in a rigid wall room or a dedicated reverberation room, place the sample on the ground and make the distance between it and any wall not less than 1.0m, while ensuring that the flushing function is normal.
[0143] 1.4.2 For floor-standing ceramic toilet samples installed close to the wall, the test can be carried out in a rigid wall room or a special reverberation room. The sample to be tested is placed on the ground so that its back is between the reflective surface of the adjacent vertical wall. The distance between the samples is 15cm±5cm, and the distance between the sample and the other three walls in the room is not less than 1.5m; at the same time, ensure that the flushing function is normal.
[0144] 1.4.3 For the floor-standing ceramic toilet samples installed near the corner, the test can be carried out in a rigid wall room or a special reverberation room. The sample to be tested is placed on the ground so that the back and sides are perpendicular to the two adjacent ones. The distance between the reflective surfaces of the wall is 15cm±5cm, and the distance between the sample and the other two walls in the room is not less than 1.5m; at the same time, ensure that the washing function is normal.
[0145] (2) Determination of sound source reference body and parallelepiped measuring surface
[0146] 2.1 The shape and size of the reference body of toilet flushing noise source
[0147] On the basis of analyzing the overall contribution of each part of the floor-standing ceramic toilet and its flushing device to the overall contribution of the flushing noise radiation, according to GB/T 3767-2016 "Acoustic sound pressure method to determine the sound power level and sound energy level of the noise source above the reflective surface The relevant provisions of Article 7.1 of the "Approximate Free Field Engineering Law" use a three-dimensional coordinate system to set the position and size of the sound source reference body; install for the three different samples 1.4.1 to 1.4.3 in this embodiment The corresponding flushing noise source reference body structure is as follows Figure 1 ~ Figure 3 Shown. When positioning the sound source reference body, the center of the box composed of the sound source reference body and its mirror image on the adjacent reflection plane is used as the coordinate origin O, and the horizontal axes x and y are respectively parallel to the length and width of the reference body . Take the horizontal length of the toilet sample as the length of the sound source reference body l 1 , Take the horizontal width of the flushing water tank as the width of the sound source reference body l 2 , Take the vertical distance from the working water level line of the water tank to the ground as the height of the sound source reference body l 3; Corresponding to different test environment conditions, the characteristic size of the sound source reference body d 0 Respectively [(l 1 /2) 2 +(l 2 /2) 2 +l 3 2 ] 1/2 (A reflecting plane), (l 1 2 +(l 2 /2) 2 +l 3 2 ] 1/2 (Two reflecting planes) and (l 1 2 +l 2 2 +l 3 2 ] 1/2 (Three reflection planes), the unit is meter (m).
[0148] 2.2 Selection of parallelepiped measurement surface and determination of microphone position array
[0149] According to the relevant provisions of Article 7.2.4 and Article 8.1.2 of the standard GB/T 3767-2016, the parallelepiped measuring surface used in the test and the sound source reference body have the same coordinate origin and appearance shape, that is, the area is S , Enveloping the flushing noise source of the toilet under test, an imaginary parallelepiped with each side parallel to the side of the reference body and the distance d from the reference body, where d≥1.0m.
[0150] 2.2.1 If the floor-standing ceramic toilet sample to be tested is installed in accordance with Article 1.4.1 in this embodiment for positioning, the corresponding parallelepiped measuring surface and its microphone position array are as follows Figure 4 As shown, the coordinates of the measuring point are shown in Table 1, where the measuring distance d=1.0m; the area S of the parallelepiped measuring surface selected is calculated according to formula (1):
[0151] S=4(ab+bc+ca)........................................ ...........(1)
[0152] In the formula: a=0.5l 1 +d, b=0.5l 2 +d, c=l 3 +d; where l 1 , L 2 , L 3 They are the length, width and height of the reference body of the sound source.
[0153] Table 1 Array coordinates of the parallelepiped measurement surface microphone position of the toilet sample on a reflecting plane
[0154] Microphone position
[0155] 2.2.2 If the floor-standing ceramic toilet sample to be tested is installed in accordance with Article 1.4.2 of this embodiment for positioning, the corresponding parallelepiped measuring surface and its microphone position array are as follows Figure 5 As shown, the coordinates of the measuring point are shown in Table 2, where the measuring distance d=1.0m; the area S of the parallelepiped measuring surface selected is calculated according to formula (2):
[0156] S=2(2ab+bc+2ca)........................................ ..........(2)
[0157] In the formula: a=0.5l 1 +0.5d, b=0.5l 2 +d, c=l 3 +d; where l 1 , L 2 , L 3 They are the length (from the wall to the front face), width and height of the reference body of the sound source.
[0158] Table 2 Array coordinates of the parallelepiped measurement surface microphone position of the toilet sample on two reflecting planes
[0159] Microphone position
[0160] 2.2.3 If the floor-standing ceramic toilet sample to be tested is installed in accordance with Article 1.4.3 of this embodiment for positioning, the corresponding parallelepiped measuring surface and its microphone position array are as follows Image 6 As shown, the coordinates of the measuring point are shown in Table 3, where the measuring distance d=1.0m; the area S of the parallelepiped measuring surface selected is calculated according to formula (3):
[0161] S=2(2ab+bc+ca)........................................ ..........(3)
[0162] In the formula: a=0.5l 1 +0.5d, b=0.5l 2 +0.5d, c=l 3 +d; where l 1 , L 2 , L 3 Are the length, width and height of the reference body of the sound source (the length of the reference body l 1 And wide l 2 , That is, the distance from the two walls to the opposite surface of the corresponding reference body).
[0163] Table 3 The parallelepiped measurement surface microphone position array coordinates of the toilet sample on the three reflection planes
[0164] Microphone position
[0165] (3) Sound pressure level measurement
[0166] 3.1 In addition to keeping a sample of the toilet to be tested and the necessary experimental equipment such as a tripod, all the other items in the test room should be removed. There should be no redundant personnel in the test room; the experiment operator should not wear clothing with obvious sound absorption characteristics; Qualified thermometers and barometers measure and record the air temperature and atmospheric pressure in the test room.
[0167] 3.2 Before performing the flushing noise test on the floor-standing ceramic toilet sample, first measure its size with a steel ruler and square ruler. 1 , L 2 , L 3 And record; according to the number of reflection planes involved in the sample installation method, determine the spatial location of the sound source reference body and calculate its characteristic size d 0; Select the applicable parallelepiped envelope sound source measurement surface and calculate its specific dimensions a, b, c; according to the microphone position array of the selected parallelepiped measurement surface, calculate and record the coordinates of each measurement point.
[0168] 3.3 The sound level meter used for measurement should meet the requirements of Type 1 instrument in GB/T 3785.1-2010, and the verification period shall not exceed 2 years; the filter shall meet the requirements of Type 1 instrument in IEC 61260:1995, and the calibration period shall not exceed 1 year. Before and after each test, a sound calibrator that meets the level 1 accuracy requirements of GB/T 15173 is used to verify it at one or more frequencies within the measurement frequency range of the sound level meter; the difference in readings Not more than 0.5dB.
[0169] 3.4 The toilet flushing noise test room can be a semi-anechoic room or a reverberation room to ensure that the volume of the available space in the test room meets the installation requirements of the ceramic toilet sample to be tested, and has the water supply/drainage conditions required for the flushing function. Pressure can be adjusted; the background noise in the semi-anechoic chamber is not more than 16dB(A), which can provide acoustic conditions similar to the free field above the reflecting surface, and the verification period is not more than 5 years; the background noise in the reverberation room is not more than 25dB(A), The reverberation time is in the range of 5s to 6s.
[0170] 3.5 In a semi-anechoic room or reverberation room that meets the above requirements, according to the microphone position array of the selected parallelepiped measurement surface, locate the coordinates of each measurement point; at the same time, move the tripod to the measurement point position and have the relevant acoustic performance The sound level meter is placed on the top of the pan-tilt to ensure that the orientation of the microphone is the same as the incident angle of the sound wave when it is calibrated, and it points perpendicular to the measurement surface.
[0171] 3.6 Take a complete normal flush cycle (half flush or full flush) as the integration time of the sound level meter's audio signal collection. If the flush cycle of the toilet sample to be tested is less than 20s, the integration time is calculated as 20s; use a sound level meter The slow-time weighting characteristic of A weighted equivalent sound level "S" determines the cumulative percentage of background noise on the selected parallelepiped measurement surface. Time average sound pressure level L pAi(B)(50) Measure 3 times continuously at each microphone position, and take the arithmetic mean value as the sound pressure level measurement value of the background noise at that position and record it. If the difference between the sound pressure levels measured 3 times at each position is greater than 0.5dB, re-measure and record.
[0172] 3.7 Adjust the test static pressure to 0.35MPa±0.05MPa, and adjust the water tank to its working water level mark, flush the toilet sample water seal to the normal water level; then, lift the toilet cover, according to the water to be tested According to the normal method, start the flushing device and start timing immediately; take a complete normal flushing cycle (half flush or full flush) as the sound level meter's audio signal acquisition integration time, if the flushing cycle of the toilet sample is less than 20s, the integration time is calculated as 20s; the A-weighted slow-time weighting characteristic "S" of the sound level meter's equivalent sound level is used to determine the cumulative percentage of toilet flushing noise on the selected parallelepiped measurement surface. Time average sound pressure level L′ pAi(ST)(50) Measure 3 times continuously at each microphone position, and take the arithmetic mean value as the measured value of the sound pressure level of the flushing noise at that position and record; if the difference between the sound pressure levels measured 3 times at each position is greater than 0.5 dB, then re-measure; at the same time record the static pressure, water consumption and flush cycle of each flush.
[0173] (4) Result calculation
[0174] 4.1 Calculation formula
[0175] With reference to relevant regulations in GB/T 3767-2016, the calculation formula for the test parameters involved in this embodiment is as follows:
[0176]
[0177]
[0178]
[0179] If △L pA(50)15dB, no background noise correction is needed; if 6dB≤△L p(50) ≤15dB, then make corrections according to formula (7).
[0180] K 1A =-10lg(1-10 -0.1△LpA(50) )……………………………………………………(7)
[0181] K 2A =l0lg(l+4S/A)…………………………………………………………(8)
[0182] When K 2A When ≤4dB, the measurement made according to the patent method is valid; the calculation formulas for the sound absorption of the semi-anechoic room and the reverberation room are:
[0183] A=α·S ν ……………………………………………………………………………(9)
[0184] A=0.16V/T n ……………………………………………………………(10)
[0185]
[0186]
[0187]
[0188]
[0189] L WA ref,atm(50) =L WA(50) +C 1 +C 2 …………………………………………………(15)
[0190]
[0191]
[0192] Where:
[0193] ——A-weighted cumulative percentage time average sound pressure level of the toilet flushing noise measured on the parallelepiped measuring surface during the normal flushing cycle, in decibels (dB);
[0194] L′ pAi(ST)(50) ——A-weighted cumulative percentage time average sound pressure level of the toilet flushing noise measured at the i-th microphone position on the parallelepiped measuring surface during the normal flushing cycle, in decibels (dB);
[0195] N M ——The number of parallelepiped measurement surface microphone positions;
[0196] ——During the normal flush period, the A-weighted cumulative percentage time average sound pressure level of the background noise measured on the parallelepiped measuring surface, in decibels (dB);
[0197] L pAi(B)(50) ——A-weighted cumulative percentage time average sound pressure level of the background noise measured at the position of the i-th microphone on the parallelepiped measurement surface during the normal flush cycle, in decibels (dB);
[0198] K 1A ——Background noise correction value;
[0199] K 2A ——Test environment correction value;
[0200] S——The area of ​​the parallelepiped measuring surface, in square meters (m 2 );
[0201] A——The equivalent sound absorption area of ​​the room at 1kHz frequency in the test room, in square meters (m 2 );
[0202] α——A-weighted average sound absorption coefficient of the surface of the test room, see Table A.1 in GB/T 3767-2016 for the value range;
[0203] S ν ——The total area (wall, floor, ceiling) of the room boundary of the test room, in square meters (m 2 );
[0204] V——The volume of the test room, in cubic meters (m 3 );
[0205] T n ——The measured A-weighted or frequency band reverberation time, in seconds (s);
[0206] ——A weighted cumulative percentage time average sound pressure level of floor-standing ceramic toilet sample flushing noise measured by the parallelepiped surface method during the normal flushing cycle, in decibels (dB);
[0207] L WA(50) ——Under the test location and corresponding meteorological conditions, the flushing noise A weighted cumulative percentage sound power level measured by the parallelepiped measurement surface method for each floor-standing ceramic toilet during the normal flushing cycle, in decibels (dB) ;
[0208] S 0 =1m 2;
[0209] C 1 ——A function of the characteristic impedance of the air under the meteorological conditions at the test time and place;
[0210] C 2 ——Convert the actual sound power under the meteorological conditions relative to the test time and location into the radiation impedance correction value of the sound power under the standard meteorological conditions;
[0211] p s ——Atmospheric pressure at the test time and location, in kilopascals (kPa);
[0212] p s,0 ——Standard atmospheric pressure, 101.325kPa;
[0213] θ——The air temperature at the test time and location, in degrees Celsius (℃);
[0214] θ 0 =314K;
[0215] θ 1 =296K;
[0216] L WA ref,atm(50) ——Under standard meteorological conditions of atmospheric pressure 101.325kPa and temperature 23.0℃, the A-weighted cumulative percentage sound power level of each floor-standing ceramic toilet sample flushing noise, in decibels (dB);
[0217] ——The average value of the A-weighted cumulative percentage sound power level of the flushing noise of each group of floor-standing ceramic toilet samples, in decibels (dB);
[0218] L WA(50)1 , L WA(50)2 , L WA(50)3 ——A-weighted cumulative percentage sound power level of the flushing noise of each group of three floor-standing ceramic toilet samples, in decibels (dB);
[0219] ——Under the standard weather conditions of 101.325kPa and 23.0℃, the average value of the A-weighted cumulative percentage sound power level of each group of floor-standing ceramic toilet samples flushing noise, in decibels (dB);
[0220] L WA ref,atm(50)1 , L WA ref,atm(50)2 , L WA ref,atm(50)3 ——Under standard weather conditions of 101.325kPa and 23.0℃, the A-weighted cumulative percentage sound power level of the flushing noise of each group of three floor-standing ceramic toilet samples, in decibels (dB).
[0221] 4.2 Data rounding requirements: A-weighted cumulative percentage time average sound pressure level L′ of toilet flushing noise and background noise pAi(ST)(50) , L pAi(B)(50) The measurement result retains one significant digit after the decimal point, and its mean value And A-weighted cumulative percentage sound power level L WA(50) The calculation result of is an integer.
[0222] 4.3 Measurement uncertainty: This patented method mainly investigates the repeatability standard deviation σ omc For the cumulative effect of measurement uncertainty, it is stipulated that the flushing noise of floor-standing ceramic toilets on the parallelepiped measurement surface A weighted cumulative percentage time average sound pressure level measurement result repeatability standard deviation σ omc The upper limit is not more than 1.5dB. Refer to the relevant content in the standard GB/T 3767-2016, in a complete normal flushing cycle, the same sound level meter is used by the same experimenter to select the same floor-standing ceramic toilet sample at the same installation position The average value of the A-weighted cumulative percentage time average sound pressure level on the measurement surface of the same parallelepiped Carry out 6 repetitive measurements (for each repetitive measurement, the toilet sample must be reinstalled and adjusted in position), and the measurement results are corrected for background noise. Repeatability standard deviation σ omc The calculation formula is:
[0223]
[0224] Where:
[0225] ——The average value of the A-weighted cumulative percentage time average sound pressure level on the parallelepiped measurement surface of the jth repeated measurement of the flushing noise of the floor-standing ceramic toilet and corrected by the background noise;
[0226] ——The arithmetic average sound pressure level calculated from all repeated measurements.
[0227] (5) Performance judgment
[0228] 5.1 Judgment basis for floor-standing ceramic toilet flushing noise
[0229] Biological studies have shown that environmental noise has a significant impact on the human body: when the noise is greater than 45dB(A), it will affect sleep; when the noise is greater than 55dB(A), it will cause emotional anxiety; when the noise is greater than 75dB(A), it will reduce learning and work efficiency ; When the noise is greater than 90dB(A), it will cause temporary hearing threshold shift; when it is greater than 140dB(A), it will cause acute ear trauma. Therefore, Article 4.1.1 of the National Compulsory Standard GB 50118-2010 "Code for Sound Insulation Design of Civil Buildings" stipulates that the allowable noise level (A sound level) in the living room of residential buildings in the day and night is 45dB, and the night noise in the bedroom shall not exceed 37dB, the daytime noise must not exceed 45dB. The national compulsory standard for quality control of related products GB 6952-2015 Sanitary Ceramics stipulates the cumulative percentage sound level of toilet flushing noise in Article 6.3 50 Should not exceed 55dB(A), L 10 Does not exceed 65dB(A).
[0230] According to the requirements of national environmental protection regulations and product standards, the following classification criteria are adopted:
[0231] In order to clean the noise very low, the environmental performance is excellent;
[0232] In order to clean the noise very low, the environmental performance is good;
[0233] In order to have lower washing noise and better environmental performance;
[0234] In order to wash with high noise and poor environmental protection performance;
[0235] For washing, the noise is very high and the environmental performance is poor.
[0236] 5.2 Judgment of the evaluation results of flushing noise of each group of floor-standing ceramic toilets
[0237] Under the test static pressure of 0.35MPa±0.05MPa, the parallelepiped measurement surface method is used to test the flushing noise of the floor-standing ceramic toilet sample during the normal flushing cycle (half flush or full flush); when a sample is flushed Noise A weighted cumulative percentage sound power level L WA(50) Greater than this group of 3 samples washing noise A weighted cumulative percentage sound power level L WA(50) Arithmetic mean When 10% of the ratio is 10%, it is necessary to re-extract a set of samples to repeat the experiment; calculate the A-weighted equivalent sound level of the sound level meter under specific static pressure conditions for the two sets of toilet samples before and after the calculation. Cumulative percentage sound power level L of flushing noise measured by hexahedral measurement surface method WA(50) Arithmetic mean of If a sample washing noise A is weighted cumulative percentage sound power level L WA(50) Greater than these two groups of 6 samples washing noise A weighted cumulative percentage sound power level L WA(50) Arithmetic mean 10% of the toilet seat, then discard; take the remaining toilet sample flushing noise A to calculate the cumulative percentage sound power level L WA(50) Arithmetic mean of As the evaluation index for the flushing noise of this group of floor-standing ceramic toilet samples.
[0238] The test facilities, equipment and test equipment used in this embodiment:
[0239] (1) Test facility
[0240] Semi-anechoic chamber: the net size of the indoor building is 9.8m×7.3m×5.9m, the effective space size after installing the sound-absorbing wedge is 7.8m×5.3m×4.9m, and the effective volume is 203m 3 , The effective use area is 41m 2. The tile floor is used as a single reflecting plane, and there are no other fixed facilities except for the corresponding water supply/drainage pipes and air conditioners; when the laboratory is operating normally and there is no abnormal interference around, the indoor background noise is lower than 14.1dB(A); The expanded uncertainty of the sound pressure level measurement result is U 95 =(0.4~1.0)dB, k=2.
[0241] (2) Test equipment and equipment
[0242] 2.1 Sound level meter: produced by Rion Corporation, model NA-28, capable of measuring equivalent continuous sound pressure L eq , Performance meets GB/T 3785 type 1 integral sound level meter regulations, filter meets GB 3241 requirements; noise analyzer preamplifier sensitivity is -27dB±2dB, A-weighted linear operation range is 25dB~130dB, peak sound level The upper limit of measurement is 143dB, the maximum value of A-weighted inherent noise is 17dB, the measurement frequency range is 10Hz~20kHz, and the sampling period is 15.6ms. Before each measurement, a sound calibrator with an accuracy of ±0.1dB is used to select 100Hz, 300Hz, 500Hz, 700Hz, 900Hz, 1000Hz and other points within the test frequency range to perform overall calibration of the relevant noise measurement system.
[0243] When the environmental conditions are 23℃, 30%RH, 102.4kPa, according to JJG 188-2002 "Sound Level Meter Verification Regulations", within the measuring range of 2Hz~200kHz, after selecting different frequency ranges for testing, the calibration result data is shown in the table 4.
[0244] Table 4 Calibration result data of sound level meter under different frequency ranges
[0245]
[0246] Uncertainty of sound pressure level U=0.4dB~1.0dB(k=2); Uncertainty of sound pressure level at reference frequency U=0.07dB(k=2); Uncertainty of calibration result is U=1.0dB( k=2).
[0247] 2.2 Sound calibrator: produced by Yiou Instrument Equipment Co., Ltd., model AWA6221A, used for absolute sound pressure calibration of sound level meters. The acoustic performance meets the accuracy requirements of GB/T 15173 in level 1; the nominal sound pressure level is 94dB and 114dB (based on 20μPa), the applicable frequency range is 1kHz~5Hz, the sound pressure level accuracy is ±0.2dB(23℃) and ±0.3dB(-10℃~50℃), the total harmonic distortion at 94dB is ≤1 %.
[0248] 2.3 Ruler: steel ruler and square ruler with 1mm graduation.
[0249] 2.4 Water seal ruler: the graduation value is 1mm.
[0250] 2.5 Thermometer: The range is 0℃~100℃, and the scale value is 0.2℃.
[0251] 2.6 Empty box barometer: the measuring range is 800hPa~1060hPa, and the maximum allowable error of indication is ±1.0hPa.
[0252] 2.7 Stopwatch: The accuracy is 0.01s.
[0253] 2.8 Tripod: made of carbon fiber or aluminum alloy, with a load-bearing capacity of more than 10kg, with a maximum height of 2.0m including the head.
[0254] The detection data and result calculation of this embodiment:
[0255] In the semi-anechoic room, the parallelepiped measuring surface method is used to detect the flushing noise of floor-standing ceramic toilets. The relevant detection data and result evaluation are shown in Table 5.
[0256] Table 5 Floor-standing ceramic toilet flushing noise detection data (a reflective plane)
[0257]
[0258]
[0259] The above are only the embodiments of the present invention, and do not therefore limit the scope of the present invention. Any equivalent transformations made using the content of the description and drawings of the present invention, or directly or indirectly applied to other related technical fields, are included in The invention is within the scope of patent protection.
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