BRUEL & KJAER 2225 User Manual

MICROPHONE ADAPTOR:
The adaptor connects the microphone to the Sound Level Meter via a
standard 5-pin DIN plug.
Note: Operating any of the following four switches; ON-OFF, RESET (BATT.), FUNCTION
SELECTOR,
or RANGE SELECTOR, causes the instrument and the timer which controls
L eq measurement and the automatic "switch-off'' facility to be reset.
ON-OFF:
RESET
(BATT.):
FUNCTION SELECTOR:
RANGE SELECTOR:
DISPLAY:
SENSITIVITY
ADJUSTMENT:
6
Push-button for switching the instrument on and off. The display
should operate immediately when switched on. The instrument
switches off automatically two minutes after last reset. This feature is
overridden when the DC OUTPUT plug is inserted.
Push-button switch which, when pressed, displays the battery condi-
tion on the scale. If the level is below the BATTERY region of the
scale, the batteries must be replaced. See Section 3. 2. This switch
also resets the meter, i.e. it starts a new measurement in 60s Leq
mode, resets the peak hold and RMS detectors and resets the auto-
matic "switch -off" time.
Four position slider - switch as follows:
"Fast" provides the standardised "Fast" detector response for measur-
ing steady sound levels.
"Slow" provides a "Slow" detector response for use when the sound
level fluctuates too rapidly in the "Fast" mode for accurate reading.
"60s Leq" Integration of the sound level takes place for a fixed period
of one minute during which the flashing display indicates the current
accummulated dose. When measurement is completed, the display
stops flashing and the 60s L eq is indicated for a read-out period of
one minute. The instrument is then automatically switched off if none
of the instrument's switches are operated during this period .
"Peak" (2225 only) holds the maximum peak value until the meter is
reset. Rise
time is 30J.LS.
"Impulse" (2226 only) Provides the "Impulse" detector response for
the evaluation of the subjective response of impulsive sounds . Note: If
an overload is detected in any mode, the display of the 2226 flashes
at full scale deflection.
A four position slider-switch for selection of four overlapping measur-
ing ranges. Windows at 1 0 dB intervals alongside the display serve to
enumerate the scale automatically.
40 dB "Thermometer" type display with 41 LEOs giving a read-out res-
olution to 0, 5 dB (two adjacent LEOs on). The display brightness is con-
trolled by a photo-transistor, and is readable even in direct sunlight.
Uppermost or lowermost LEDs indicate out-of-range.
Removing a small plastic plug gives screwdriver access to the poten -
tiometer . The gain may be adjusted (over a 1 0 dB range) to allow for
small variations in microphone or meter sensitivity.

BRUEL & KJAER 2225 Specifications

General

Brand	BRUEL & KJAER
Model	2225
Category	Measuring Instruments
Language	English