BRUEL & KJAER 2221 - Display Symbols and Indicators

POWER:
RESET:
Two positions slide-switch connecting power to the instrument.
Resets the time and dose counters plus max. hold detector. The mea-
surement starts after 0,5 s delay in order to avoid switching noise.
SENSITIVITY ADJUSTMENT:
Multiturn potentiometer to calibrate the instrument sensitivity. Sensitiv-
ity is increased when turning clockwise. Access to the potentiometer is
protected by a removable plastic lug.
AC OUTPUT:
DISPLAY:
2,5 mm mini-jack socket accepting Plug JP 0213 and Cable AO 0173 for
level recording. The maximum signal delivered is 2 V RMS and corre-
sponds to full range. Output impedance 1 kn, short circuit protected.
Fig . 2.2. AC Output of the Sound Level Meter
3112 digit liquid crystal display for readout of measurement results and
the following indications:
"0 0.0": Displayed for one second after switching on. This display is
followed by " " in order to check visually all segments of the
display.
. -, .-, .-,A
Lf Lf.Lf
---A
b) 1;;;:=:::=:====:3
Fig. 2.3. a) Display check
b) Underrange in Max.
Hold (and Reset)
BAT I .-, ·= ·-·A
f ,_, L.l. '
a) ~ ---------------- ··
-, ' .-,*
f f.=f A
b) E=:===::z:=•
Fig. 2.5. a) Battery depleted
b) Maximum Leq
duration exceeded
-, I t:IA
f •• _,
~ ,.-,.- t'
f Lf 0 . -,A
b) IIIIIEIII!Ii!IIBIEE!!II
Fig . 2.4. a) Underrange
b) Overload
•_=, t_l ,-,A
I.L.f
.-, .-, .-
=- ct=• L
Fig. 2.6. a) A-weighting applied
b) Linear (Flat)
weighting applied
7