CN201346205Y - Acoumeter testing device - Google Patents

Abstract

The utility model discloses an acoumeter testing device, which comprises a fictitious load (1), a band-pass filter (2), a voltage testing unit circuit(4), a frequency testing circuit (3), an arithmetic unit (5) and a display output device (6). The fictitious load (1) provided with a standard earphone connector (7) is connected with the band-pass filter (2) and the frequency testing circuit(3) respectively; the input terminal of the voltage testing unit circuit(4) is connected with the band-pass filter (2), and the output terminal thereof is connected with the arithmetic unit(5); and the frequency testing circuit(3) and the display output device (6) are connected on the arithmetic unit(5). The utility model meets the testing requirements of routine items for a common acoumeter user; and the testing accuracy reaches international and national regulations. In addition, the utility model has the advantages of fewer accessories, simple operation, low price and the like.

Description

A kind of sonometer test set

Technical field

This utility model relates to a kind of test set, particularly a kind of test set that is used for sonometer.

Background technology

In processes such as the exfactory inspection of sonometer product, maintenance, calibration, all need the signal output situation of sonometer is tested, and, because the particularity of sonometer use occasion, such as aspects such as clinical diagnosis, researchs, index request to its output signal is very high, and the controllability of its output signal and accuracy directly influence the effect of various diagnosis, research work.At present, the sonometer test is mainly tested by equipment such as artificial ear or artificial ear, sound meter and computers, the artificial ear or the artificial ear of different earphone correspondences respectively have a cover, in the testing hearing timing, the earphone of the variant model of sonometer is placed on the corresponding artificial ear or artificial ear, gather acoustical signal by the computer control sound meter, thereby test accordingly.On the one hand, the check of sonometer and calibration all need often to carry out, and existing testing equipment kind complexity, quantity are more, not only operation inconvenience, and cost an arm and a leg, can't satisfy the needs of daily detection; On the other hand, sensitivity of sonometer earphone special and concordance are fine, adopt signal of telecommunication method of testing can well realize the detection effect of sound test method.

The utility model content

The purpose of this utility model is to provide a kind of sonometer test isolated plant, adnexa is few, simple to operate, cheap, under sensitivity of sonometer earphone special and the good actual prerequisite of concordance, it can satisfy the conventional project testing requirement of common sonometer user, and test accuracy reaches international, national regulation.

For solving above-mentioned technical problem, this utility model by the following technical solutions:

A kind of sonometer test set, constitute by fictitious load, band filter, voltage tester element circuit, frequency test circuit, arithmetical unit, demonstration outut device, the fictitious load difference connecting band bandpass filter and the frequency test circuit that have the standard earphone joint, voltage tester element circuit input is connected, exports termination arithmetical unit with band filter, the frequency test circuit with show that outut device also is connected on arithmetical unit.

Further technical scheme is, described fictitious load is a variable resistance.

Further technical scheme is, described band filter is a narrow band filter.

Compared with prior art, the beneficial effects of the utility model are that adnexa is few, test process is simple, test value that obtain is accurate, cheap.

Description of drawings

Fig. 1 is this utility model principle block diagram;

Fig. 2 is this utility model structural representation;

The specific embodiment

The theory of testing of the present utility model and operation principle are: when test, the sonometer earphone is replaced to fictitious load, the resistance setting of fictitious load is consistent with earphone impedance, tests accordingly by the mode of gathering the signal of telecommunication.During test sound intensity accuracy, the frequency of sonometer output regulation and the sound of the sound intensity are in fictitious load, and the gained signal of telecommunication one tunnel enters band filter, carry out input voltage test cell circuit after the filtering, obtain magnitude of voltage accurately; Another road enters the frequency values that the frequency test circuit obtains signal, and magnitude of voltage and frequency values are fed to computing wherein, and calculate actual acoustic pressure that sonometer export according to sound pressure level arithmetical unit, calculates the accuracy of each frequency of sonometer according to the frequency accuracy formula.

The sound pressure level formula:

$\mathrm{SPL}=20{\log }_{10}\frac{p}{p_0}---\left(1\right)$

$V=\sqrt{\mathrm{WR}}---\left(2\right)$

p＝MV (3)

Wherein: SPL is the sound intensity

P is an acoustic pressure

p ₀Be normal atmosphere (20 * 10 ^-6) handkerchief

V is a voltage

W is a power

M is a kinetic energy

Frequency accuracy formula=f/f ₀* 100%

Wherein: f is a test frequency

f ₀Be standard frequency

Before calculating sound pressure level, kinetic energy M that should first test earphone at first calculates magnitude of voltage when promoting earphone and reaching the earphone sensitivity sound intensity according to formula (2), calculates acoustic pressure P according to formula (1) again, calculates kinetic energy M according to formula (3) at last.When formal test, according to actual test voltage value V and the kinetic energy M that calculates, calculate acoustic pressure P according to formula (3) again, calculate sound pressure level SPL according to formula (1) at last.

As shown in Figure 1, fictitious load 1 is a variable resistance, be connected with frequency test circuit 3 with band filter 2 respectively, band filter 2 adopts narrow band filter, band filter 2 is connected with voltage tester element circuit 4, voltage tester element circuit 4 adopts 51 single-chip microcomputers to carry out collecting test, frequency test circuit 3 adopts 51 single-chip microcomputers to carry out collecting test, arithmetical units 5, input was connected with frequency test circuit 3 with voltage tester element circuit 4 respectively, adopt dsp chip to constitute arithmetical unit 5, arithmetical units 5, outfan connected demonstration outut device 6, showed that outut device 6 is a LCD liquid crystal display screen.

Impedance with tested sonometer conductance earphone is 60 Ω, earphone sensitivity is that 106dB/mw is an example, the resistance of fictitious load 1 is preset as 60 Ω, then the standard earphone joint 7 in the fictitious load 1 is connected on the sonometer earphone interface, the operation sonometer sends the signal of conductance earphone 1000Hz/100dB, the signal of telecommunication one tunnel through fictitious load 1 is input to band filter 2, band filter 2 is exported the signal of telecommunication of 1000Hz to voltage tester element circuit 4 according to frequency test signal, the voltage that voltage tester element circuit 4 is tested is 0.138V, and calculate sonometer output sound pressure level according to the sound pressure level formula arithmetical unit 5 is 101dB.The signal of telecommunication one tunnel through fictitious load 1 is input to frequency test circuit 3, and the actual frequency that frequency test circuit 3 is tested are 1001Hz, and calculate sonometer output frequency accuracy according to the frequency accuracy formula arithmetical unit 5 is 99.9%.

Claims (3)

1. sonometer test set, it is characterized in that it is made of fictitious load (1), band filter (2), voltage tester element circuit (4), frequency test circuit (3), arithmetical unit (5), demonstration outut device (6), fictitious load (1) the difference connecting band bandpass filter (2) and frequency test circuit (3) that have standard earphone joint (7), voltage tester element circuit (4) input is connected, exports termination arithmetical unit (5) with band filter (2), and frequency test circuit (3) also is connected arithmetical unit on (5) with showing outut device (6).

2. sonometer test set according to claim 1 is characterized in that described fictitious load (1) is variable resistance.

3. sonometer test set as claimed in claim 1 or 2 is characterized in that described band filter (2) is a narrow band filter.

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