Sound intensity Probe Type 50AI comprises:
- Sound Intensity Microphone Pair Type 40AK
- Two Microphone Preamplifiers Type 26AA
- Four solid spacers of various lengths
- Remote-control handle
The microphones are high sensitivity, free-field 1⁄2-inch condenser microphones with a uniquely designed pressure equalisation system which ensures extremely well defined phase characteristics. The microphones and preamplifiers are mounted on a swivel head on the telescopic arm of the Remotecontrol handle. To cover the full frequency range from 50 Hz to 10 kHz, the Type 50AI probes are delivered with four solid spacers for spacing the microphones at 12 mm, 25 mm, 50 mm and 100 mm. These spacers can be easily interchanged without dismantling the probe.
Microphone Type 40AK
- Sensitivity 25 mV/Pa
- Dynamic range 21 – 152 dB re. 20µPa
- Frequency response – IEC 60651 Type 0
- Phase response – IEC 1043 Class 1
- Polarisation voltage 200 V
- Diameter 13.2 mm
Preamplifier Type 26AA
- Frequency response – 2.5 Hz – 200 kHz, ± 0.2 dB (18pF/small signal)
- Slew rate – 20 V/μs
- Input impedance 20 GΩ, 0.5 pF
- Output impedance 75 Ω
- Gain 0.27 dB
- A-weighted noise ≤ 2.5 μV rms
- Linear noise (20 Hz – 20 kHz) ≤ 6 μV rms