Chapter 1 — Introduction
Detectors
2238 Mediator Integrating Sound Level Meter
Service Manual
BI5043–13
3
Fig.1.1 Simplified block diagram for 2238 Mediator
1.5 Detectors
One of the main features of Mediator is that it contains two detectors with independ-
ent frequency weighting functions. In the basic package, one is an RMS detector and
the other a Peak detector. Linear and A- and C-weighting can be selected for both
detectors. F (Fast), S (Slow) and I (Impulse) time weighting must be selected in the
basic version. Both frequency and time weightings must be selected before a meas-
urement is performed in the basic package. In other packages F, S and I are measured
in parallel.
1.6 Application Programs
● Basic Software BZ7126 – General purpose SLM functions featuring: Independently
weighted RMS and Peak detectors in parallel, pre-selected F, S, and I time con-
stants, all parameters for occupational health work – Exchange rate = 3 plus ei-
ther 4 or 5, manual control or preset time with automatic storage, 500
measurement files, corrections for windscreen effects and sound incidence, AC
and DC outputs, serial interface control,
L-filter
MUX
Aux 1
Aux 2
A-filter
C-filter
Overload detector
1/1- and 1/3-Octave
Filter Set
Correction filter
(Sound Incidence,
Windscreen)
Amplifier
10 dB/step
(Cal. adjustment)
Preamplifier
MUX
Buffer
AC out
RMS
detector
Time weighting
1
Buffer
DC out
Peak/RMS
2
detector
Digital control
and processing
Power supply
Display
Keys
Microphone
RMS 1 RMS 2
3
PEAK AUX1/2
3
External
power
supply
980091e
Batteries 6V
(4 x AA size)
Serial
interface
1
No time weighting with peak detector
2
Only peak detector in basic version
3
Not available in Basic Version