BRUEL & KJAER 2203 Instructions And Applications

5.5. EFFECT OF TEMPERATURE
The temperature stability of the 2203 is such that overall instrument
gain will not change by more than ± 0, 5 dB in the range of -20° to
+ 50°C. Many of the gain changes with temperature of various parts of
the instrument are opposite and thus to a large extent cancel each
other .
The Microphone sens1t1v1ty varies less than ± 0,2 dB within the op-
erating temperature range of the instrument. These changes are nearly
random and vary unpredictably from microphone to microphone.
The effect of temperature on the RMS indication is shown in Fig . 5.9.
dB ~::::::::1 ::::::=====i=;J
-20
-10
0
10
20 30 40
713495
Fig . 5. 9. Effect of temperature on amplifier and RMS circuit
5.6. EFFECT OF HUMIDITY
The Microphone is unaffected by humidity as long as no condensation
occurs inside it . The microphone cap contains silica gel which absorbs
moisture during storage and prevents condensation. For the instrument
as a whole, the effect of humidity is negligible (less than 0,5 dB) up to
90% relative humidity.
5.7. INHERENT NOISE LEVELS
The lower level limit of measurement is determined by the inherent
noise of the instrument and also depends on the weighting network
used.
Fig .5.
10 shows typical inherent noise levels for the 2203 when used
with the Octave Filter Set 1613 and one or half-inch Microphones. The
lines marked "Spec." show the lower limits of the instrument as speci-
fied by B & K. The shaded areas show typical values of the inherent
noise.
39

BRUEL & KJAER 2203 Specifications

General

Brand	BRUEL & KJAER
Model	2203
Category	Measuring Instruments
Language	English