BB106411.book : 2237-ch3 Black 12
Chapter 3 – Taking Measurements
Reading the Parameters
3–12
Brüel & Kjær2237 Controller
User Manual
Peak The maximum peak level within the last one second
interval.
MaxL Maximum sound pressure level (SPL) over the
elapsed measurement time.
MinL Minimum sound pressure level (SPL) over the
elapsed measurement time.
SPL The maximum sound pressure level within the last
one second interval. This parameter is the numer-
ical equivalent of the level indicated by the quasi-
analogue display. It differs from the peak value
because SPL is an RMS (root mean square) meas-
urement.
Inst A randomly sampled instantaneous sound level
within the last one second. Generally, it shows a
smaller value than SPL.
The values of the RMS value parameters (SPL, MaxL, MinL,
L
eq
and Inst) are affected by the time weighting setting (see
section 3.4.2). The time weighting is shown on the display
next to the relevant parameters. The RMS parameters always
have an “A” frequency weighting.
Consult your local authorities for regulations concerning
which parameters you need to monitor and which time
weighting you should use. In general, L
eq
and MaxP meas-
ured with a Fast time weighting are required.
The peak value parameters (Peak and MaxP) are not affected
by the time weighting.
The following codes are displayed to indicate the applied
frequency and time weightings:
AF “A” frequency weighting and Fast time weighting
AS “A” frequency weighting and Slow time weighting
AI “A” frequency weighting and Impulse time weighting
To Next Page
Loading...
