Svantek SV 33A User Manual

INSTRUMENTATION FOR

SOUND AND VIBRATION MEASUREMENTS

SV 33A

Acoustic calibrator

User’s manual

Warsaw, March 2017

SVANTEK Sp. z o.o. www.svantek.com e-mail: office @ svantek.com.pl

02-872 Warszawa, ul. Strzygłowska 81 tel./faks: [phone]

VAT EU PL5270105272 REGON 002175672 KRS 000192065

Registered in the Warsaw District Court, XII Economic Department Initial Capital 100 000 PLN

SV 33A USER MANUAL.

Contents

1. Introduction ........................................................................................................... 2

1.1. Calibration .................................................................................................... 2

1.2. Accuracy of calibration ................................................................................. 2

1.3. Classification of sound level meters and acoustic calibrators ....................... 2

2. Acoustic calibrator SV 33A ................................................................................... 3

2.1. General description ...................................................................................... 3

2.2. Usage of the calibrator ................................................................................. 4

2.2.1. Button functions .................................................................................... 4

2.2.2. Indicators .............................................................................................. 5

2.3. Replacing the battery ................................................................................... 6

3. SV 33A Datasheet ................................................................................................ 8

1

SV 33A USER MANUAL

.

1. Introduction

1.1. Calibration

One of the fundamental questions that are most frequently asked while taking
a measurement is whether its result is accurate. Proceeding with a measurement
without having a positive answer to this question may result in obtaining data of
no practical use and wasting our time. However, we may easily obtain the answer
by performing a calibration of the sound level meter together with the microphone
and its preamplifier. Calibration of the measurement device may be done in two
ways: by comparing the calibrated device with a reference device of known
parameters; or using a template of the measured quantity to perform a reference
measurement. Acoustic devices are usually calibrated in the latter fashion with
so-called, acoustic calibrators. Acoustic calibrator is a device, which produces
acoustic pressure of defined level and frequency. In other words, such calibrator is a
template of acoustic pressure. With help of such a template we can check the
accuracy of the measurements performed with the sound level meter and/or calibrate
it if the error occurs.

1.2. Accuracy of calibration

Each measurement performed with any measurement device is burdened with
an error. Result obtained from such measurement is only an estimate of the real
value of the measured quantity. It is impossible to remove the error completely,
as the values given by the meter are discrete whereas the measured quantity is
of continuous nature. Hence, the purpose of calibration is to limit this inevitable error
to a certain acceptable level. Maximum absolute value of the error of measurement
(or of the generated signal in the case of the calibrator) is called the tolerance and is
strictly defined by the standards for the given type of device.

A sound level meter is calibrated correctly if and only if the measurement error
is within the range of tolerance defined by the standards for the meter of a given
class.

1.3. Classification of sound level meters and acoustic calibrators

The acoustic calibrators (see IEC 60942: 2003) and the sound level meters
(see IEC 61672: 2002) are divided into classes and types respectively, according to
their accuracy. Type 0 imposes the strictest requirements on the device. Devices of
this class are ranked as the most precise. Each of the following types (1, 2 and 3)
allows for the wider range of tolerance (see Table 1).

Table 1. Tolerance values for the given types of acoustic devices excluding maximum expanded
uncertainty of measurement (f = 1 kHz)

Class / Type
Sound level meter, [dB]
Acoustic calibrator, [dB]

2

LS 1 2

- 0.7 1.0

0.10 0.25 0.40