HD 9101 Sound Level Calibrator type 1 IEC 60942.
Calibration frequency 1000Hz, sound pressure levels 94dBand 114dB.

The HD 9101 sound level acoustic noise generator is a battery-fed portable sound source, suitable for calibrating sound level meters (portable and laboratory versions) and acoustic measuring stations. 
The advantages of the HD 9101 calibrator are the following:
With the frequency of sound pressure at 1000 Hz, calibration may be carried out without correction factors, irrespective of weightings A, B, C and D.
The HD 9101 calibrator may be used conveniently in the laboratory and in the field.

The sound pressure generated is independent of atmospheric pressure, so it is not necessary to correct the value to suit the atmospheric pressure (contrary to pistonphones which require correction).

Large calibration equivalent volume: the volume between the microphone and the generator and the equivalent volume of the microphone do not have an appreciable influence on the measurement
(the coupling between the microphone and the calibrator may be loose).

It is simple to use, so it may be used even by non-skilled operators.

TECHNICAL DATA

The HD 9101 calibrator satisfies the requirements of class 1 according to standard IEC 60942-1988 and the requirements of the ANSI SI.40-1984 standard.
Diameter of the microphones that can be calibrated:
23.77 ±0.05 mm 1", 12.7 ±0.03 mm 1/2" (with 1/2" adaptor mod. 9101040), standard dimensions according to IEC 61094-1 and IEC 61094-4
Stabilization time: 60 sec
HD 9101 Frequency: 1000 Hz ±2%
HD 9101 Sound pressure level:
94 dB/114 dB ±0.3 dB

Total distortion: <0.5%
Influence of static pressure (Ref. 101.3 kPa):
±0.1 dB between 90 kPa and 108 kPa
±0.3 dB between 65 kPa and 108 kPa
Influence of temperature (Ref. 23°C):
±0.05 dB between 5°C and 35°C
±0.2 dB between -10°C and 50°C
Influence of relative humidity (Ref. 50% R.H.):
±0.1 dB between 10% R.H. and 90% R.H. without condense
Stability (one year with normal use): ±0.1 dB
Working temperature: -10 ÷ +50°C
Storage temperature: -25 ÷ +55°C
Relative humidity: ≤90% R.H.
Equivalent volume of the calibration chamber (+23°C):
10 cm3
Power supply: IEC 9V alkaline battery type 6F22
Battery lifetime: about 15 hours with alkaline battery
Container material: NORYL NE110 resin
Dimensions: mm 160x140, H=46 mm
Weight: 400 gr.