Casella 620 Series - Additional Information for Testing; Reference Sound Pressure Level; Reference Level Range; Microphone Reference Point

620 Series
28
Additional information required for
testing
As required by IEC61672-1 section 9.3
a) Reference Sound Pressure Level
The reference sound pressure level is selectable to be 94 dB or 114 dB.
b) Reference Level Range
The CEL-62X is a single level range instrument of 0 to 140 dB.
c) Microphone Reference Point
The microphone reference point is the centre of the diaphragm of the microphone. The 0
o
reference direction is perpendicular to the microphone diaphragm.
d) Acoustical Frequency Response Testing
The pressure to free field correction data for the CEL-251 microphone used for periodic testing.
Frequency
0
o
Free Field
Corrections using a
Bruel & Kjaer 4226
Calibrator
0
o
Free Field
Corrections with
Wind Screen using a
Bruel & Kjaer 4226
Calibrator
0
o
Free Field
Corrections using a
Bruel & Kjaer
UA0033 Electrostatic
Actuator
0
o
Free Field
Corrections with
Wind Screen using a
Bruel & Kjaer
UA0033 Electrostatic
Actuator
Expanded
Uncertainty
of
Corrections
at 95%
probability
(k=2)
Hz
dB
dB
dB
dB
dB
31.5
-0.1
-0.1
-0.1
-0.1
0.2
63
-0.2
-0.2
-0.2
-0.2
0.2
125
-0.2
-0.2
-0.2
-0.2
0.2
250
-0.2
-0.2
-0.2
-0.2
0.2
500
-0.2
-0.2
-0.2
-0.2
0.2
1000
0
0.1
0
0.1
0.2
2000
0.3
0.7
0.3
0.7
0.3
4000
0.7
1.4
0.8
1.5
0.3
8000
2.8
2.5
3.1
2.8
0.4
12500
5.3
4.1
6.2
5.0
0.6
16000
6.4
4.5
7.8
5.9
0.6
e) Linear Operating Range
The lower and upper limits of the linear operating ranges (dB)for electrical input, or using a CEL-
251 microphone; (add 10dB to the lower limit when using a CEL-252 microphone).