az-instrument 8930 User manual

8930A, for 23.8mm diameter 8930B, for 13.2mm diameter
8930C, for 12.2mm diameter 8930D, for 7mm diameter

INTRODUCTION
1
This compact sound level calibrator is a
portable, battery operated sound source,
suitable for many portable sound level
meters. When a microphone from a sound
level meter is inserted into this calibrator,
the sound level meter picks up the signal
and displays the signal in dB (decibel) units.
The sound level meter should be adjusted
(if necessary) to match the calibrator's
output signal as closely as possible.
This calibrator provides a stable reference
level across changes in many environmental
conditions. Corrections for variations in
atmospheric pressure are not required.
The system emits the signal through the
microphone cavity. An outer capillary hole
balances the chamber static pressure
protecting microphones from overpressure
due to their insertion.
The generated sound pressure level is
equal to 94dB, 104dB and 114 dB at 1000 Hz
frequency. The 1000 Hz frequency allows
calibrating sound level meters with any
frequency weighting (LIN, A, B, ...), Wi thout
applying any correction factor. The generated
sound pressure level is independent of
atmospheric pressure, users don't need to
adjust the value according to static pressure
over a wide range of values.
It can be conveniently used both in laboratory
and in the field. The 114 dB sound level
allows performing calibrations even in high
background noise environments.
There are total 4 models allow calibrating
different size microphones with
mechanical dimensions compliant with
IEC 61094-1and IEC 61094-4.

Features:
Meet IEC 60942:2018, class 2 standard
Suitable for all sound level meter with
microphone head mechanical compliant
with IEC 61094-1 or IEC 61094-4,
such as 23.8/13.2/12.2 and 7mm
Calibration frequency at 1K Hz with
three level 114dB, 94dB and 104dB
Vivid LED display with stability and
low power indicator
Power up by batteries, easy to carry
around
MATERIAL SUPPLIED
Meter (check if the microphone
cavity diameter meets your need)
2pcs AA alkaline batteries
Operation manual
Hard carrying case
2
POWER SUPPLY
Regular or alkaline battery are both fine
to use in this calibrator.
A complete sound level calibrator
package contains of the following items.
There are total 4 models allow calibrating
different size microphones with
mechanical dimensions.
The battery compartment is in the rear
side of the detector. Open the battery
cover and install 2pcs AA size batteries
in correct polarity and in good contact.
The power LED turn into red color while
measured battery voltage is below 2.2V
. Please change 2pcs new AA batteries
to ensure accurate reading.

3
CAUTION
1. Before operation, leave the calibrator
in stable room temperature for at least
2 hours to make calibrator reach
temperature equilibrium.
2. Make sure the microphone and the
calibrator are correctly aligned during
insertion because the microphone
could be damaged if not inserted
squarely, or if inserted at speed or if
excessive force is used.
3. The calibrator need to be placed on a
flat surface. While measuring, you
should move neither the microphone
nor the calibrator; make sure that the
worktable doesn't transmit vibrations.
4. During calibration, if the environmental
conditions are not respected, such as
-Ambient noise is too large
-Shocks given involuntarily
Wait for the stabilization before resume
the calibration process.
5. This is a very precision instrument and
should be treated with care. Avoid below
and use hard carry case to store and
protect the instrument.
-Physical shocks or drops
-Ingress of dirt, dust and other foreign
objects into the sound cavity
-Exposure to water droplets or
condensation