Microphones de mesure




The 5002 Pistonphone is a compact mains-intependent precision sound pressure source of class 1L according to DIN IEC 942 (1990) for fast and precise calibration of sound level meters and complete sound measuring systems. It provides an easy and quick method for calibration and requires only low maintenance. The 5002 Pistonphone enables to calibrate measuring microphones with capsule diameters of 1”, 1/2” and 1/4” as well. Using 1/2” and 1/4” capsules, corresponding adapter rings being part of delivery are required. In addition to the microphone capsules offered by the manufacturer Microtech Gefell, microphone capsules of other make can be used provided they have the same diameter. Should the equivalent microphone volume deviate, this has to be taken into account by means of a correction factor.

Construction and Operating Principle:

A low noise DC motor moves two pistons by means of a cam disk in a pressure chamber. A steady-state sinusoidal alternating sound pressure is produced by oscillating pistons in the pressure chamber, close by the microphone to be calibrated. The generated sound pressure level of 124 dB is so high that surrounding noise does not effect its operation.

The high sound pressure level allows the calibration of 1/4” measuring microphones. The revolutions per minute of the motor and thus the frequency of the sound pressure level is kept constant by a quartz-stabilized circuit independet from the battery voltage. The faultless operation of 250 Hz is shown by a green LED. Should the operation voltage decreases below the allowable limit, a red LED starts shining. The unit is powered from seven 1,5 V primary cells of the type LR 6. Further it can be powered from an external DC source with a voltage range from 8 to 45 V, 100 mA, e.g. from a customary in trade plug power supply with 2,5 mm jack connector – positive pole to center contact. Because the generated sound pressure level depends on the static barometric pressure the pistonphone is supplied complete with a barometer having special scale on which the corresponding level correction values can be read directly. The 5002 Pistonphone and its accessories as well are supplied in an eye-catching case made of luxury wood.


Pistonfon 5002 in a wooden case
L x B x H    310 x 125 x 70 mm with
Adaptor for 1/2” microphones  5002 – 2
Adaptor for 1/4” microphones  5002 – 3
Correction Barometer                5002 – 4
Order-No. 313003


Holder for both 1/2”- and 1/4”- measuring microphone  5002 – 5
Order-No. 303004


Sound pressure calibrator Class 1L DIN IEC 942 (1990)
Class 0L with suitable external barometer
Pistonfon 5002
21.51 – 00.03   PTB-licence no. for official calibration
Nominal sound pressure level
124 dB
Nominal frequency
250 Hz
Tolerance of sound pressure level
± 0,3 dB
Total harmonic distortion
    3 %
Tolerance of frequency
 0,1 %
850 hPa … 1080 hPa
Temperature, operating
– 10°C bis + 50°C
Temperature, storage
– 40°C bis + 70°C
Relative humidity
max 95 %
Power supply
7 Primärelemente LR6 / 1,5 V
Livetime with alkaline batteries at 20°C
> 30 Std.
Degree of protection
IP 30
Dimensions    L x B x H
180 mm x 64 mm x 48 mm
Weight with batteries
Complete with wooden case
670 g
1530 g



Delivery Pistonphon 5002

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