Instruction Manual

Sound Level Meter Types 2245 – Instruction Manual Page 60 of 110
4.10.2 Linear Averaging
Linear Averaging Times: 1 second to 24 hours, in steps of 1 second
Settling Time According to IEC 60804: <2 seconds
Nominal Delay Time between operation of the reset facility and re-initiation of a
measurement according to IEC 61672–1: <3 seconds
Time Interval after completion of a measurement before a reading is
displayed according to IEC 61672–1: <1 second
Minimum Hold Time according to IEC 60804: Results of a Timed Measurement are
held until a new measurement is initiated or the result is reset.
4.10.3 Peak
Peak Onset Time according to IEC 60651: <100 μs
4.11 Spectrum Analysis
Analytical Filter Design: Optimised Z-transformation of analogue Butterworth filters
Base: 10
Sampling Rate: Octave-based down-sampling from 65.536 kHz
Reference Attenuation: 0 dB, relative to the broadband equivalent continuous Z-
weigthed sound level L
Zeq
for a 1 kHz sinusoidal input
4.11.1 1/1- octave Band Centre Frequencies
Nominal: 16 Hz, 31.5 Hz, 63 Hz, 125 Hz, 250 Hz, 500 Hz, 1 kHz, 2 kHz, 4 kHz, 8 kHz, 16
kHz
Exact (5 digits): 15.849 Hz, 31.623 Hz, 63.096 Hz, 125.89 Hz, 251.19 Hz, 501.19 Hz,
1 kHz, 1.9953 kHz, 3.9811 kHz, 7.9433 kHz, 15.849 kHz
Real-time Frequency Range (Time-invariant Range): 16 Hz to 16 kHz centre
frequencies.
Fig. 4.15 The shapes of the 1/1-octave band filters (from 0 to –80 dB). The
innermost and outermost curves show IEC 61260 limits