Reference Only

P 5 / 6

MURATA MANUFACTURING Co., LTD.

Rev.N

Measuring Circuit

Fig. 2: Murata standard measuring

Condition : U.S. and S.C.M must be aligned with the line of SP., and fixed distance: 30 cm when

measuring.

An input Sound Pressure Level is 94 dB at 40 kHz.

How to measure a temperature characteristic :

After inputting a product into the thermostatic chamber in 15 min. or more,

Measure the product according to the above method immediately

SP.

S.C.M.

30 cm

U.S.

Amp.

OSC.

Freq. Counter

Voltmeter

OSC.

:

Oscillator

(Brüel & Kjær 1013)

U.S.

:

Ultrasonic Sensor

S.C.M

:

Standard Condenser Microphone

(Brüel & Kjær 4135)

Amp.

:

Amplifier

(Brüel & Kjær 2610)

SP.

:

Tweeter

RL

:

3.9 k ohm

RL