BRUEL & KJAER 2225 User Manual

Instruction Manual
Integrating Sound Level Meter Type 2225
Integrating Impulse Sound Level Meter Type 2226
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Briiel•l( j ar ~ Type 22211
033-0523
Two portable Sound Level Meters with easy-
to-read
"thermometer" display, complying
with IEC 651 Type 2*, DIN 45634 and
ANSI S1 .4 - 1971 Type S2A. An A-weight-
ing network is built-in. "Fast" and "Slow"
time constants and a one minute L eq easily
converted to SEL (LAx) on both meters. In
addition the 2225 has a "Peak" hold and
the 2226 an "Impulse" function and "Max.
hold" facility on all time constants. The
measuring range from 25 dB(A) to
1 40 dB(A) peak is covered in 4 overlapping
40 dB(A) ranges. Automatic reset and other
features enable operators to make accurate
valid measurements after a short period of
familiarisation. DC output to a level recor-
der.
Supplied with Prepolarised Condenser Mic-
rophone Type 4175
• except for "Max . hold" on 2225
+ BrUel & Kjaer

BRUEL & KJAER 2225 Specifications

General

Weighting	A, C, Linear
Detector	True RMS
Measuring Range	30 - 140 dB
Time Constant	Fast, Slow
Time Weighting	Fast, Slow
Display	LCD with backlight
Power Supply	4 x AA batteries or external power supply
Calibration	Internal or external acoustic calibrator
Standards Compliance	IEC 61672

Summary

Introduction to Sound Level Meter Operation

Short-term Leq Measurement Concepts

Explains the concept of Leq and short-term measurements.

Calibration and Description

Instrument Calibration Procedure

Details the steps for calibrating the sound level meter.

Instrument Description and Design

Overview of the meter's internal structure and components.

Technical Specifications of 2225 and 2226

Performance and Environmental Specifications

Covers measuring range, frequency response, detector characteristics, and environmental effects.

Controls and Indicators

Front Panel Controls and Labels

Identifies and describes front panel components like selectors and indicators.

Control Details and Outputs

Operational Switches and Selectors

Explains the operation of ON-OFF, RESET, FUNCTION, and RANGE switches.

Display and Sensitivity Adjustment

Details the LED display and sensitivity tuning potentiometer.

DC Output and Mounting Bush

Describes the DC output socket and tripod mounting thread.

Operating Procedures

General Operating Guidelines

Covers storage, handling, and initial setup considerations.

Battery Installation and Microphone Mounting

Instructions for installing batteries and attaching the microphone.

Measurement Procedures

Sound Level Measurement Procedures

Outlines the general procedure for performing sound level measurements.

Specific Measurement Modes

Details operation for Fast, Slow, Leq, Peak, and Impulse modes.

Noise Dose and SEL(LAX) Measurements

Procedures for calculating noise dose and Sound Exposure Level.

Use with Other Instruments

DC Level Recording Setup

Guide for connecting and using the meter with a level recorder.