BRUEL & KJAER 2240 - Measuring Range; Primary Indicator Range

Integrating-averaging Sound Level Meter Type 2240 – Instruction Manual18
4.8.1 Maximum Broadband Self-generated Noise
4.8.2 Typical Broadband Self-generated Noise
4.9 Measuring Range
4.9.1 Maximum Sound Level
The maximum sound level that the system can accomodate without causing damage to the system is
146 dB.
4.9.2 Total Range
The difference between the upper limit on the least sensitive level range, and the lowest sound pressure
level measurable on the most sensitive level range, which can be measured at 1 kHz within the most
conservative tolerance limits, specified in the International Standards IEC 60651, IEC 60804 and
IEC 61672 – 1:
4.9.3 Primary Indicator Range
Table 4.2
Maximum broad-
band, self-gener-
ated noise
Frequency
Weighting
A-Weighting C-Weighting
Electrical 18.0 18.0
Microphone 18.0 19.0
Total 21.0 21.5
Table 4.3
Typical broad-
band self-
generated noise
Frequency
Weighting
A-Weighting C-Weighting
Electrical 14.5 16.0
Microphone 16.5 17.5
Total 18.6 19.8
Table 4.4
Total range
Frequency Weighting
Microphone
Configuration 1
A-weighting (dB) 140 – 30
C-weighting (dB) 140 – 30
Table 4.5
Primary Indicator
Range according
to International
Standard
IEC 60651
Range Name
Upper Limit
(dB)
Lower Limit
A-weighting (dB) C-weighting (dB)
1 140 60 60
2 110 30 36