Norsonic’s range of microphones covers most application and can be used as direct replacement with other brands. Full use has been made of modern materials which when coupled with traditional engineering skills produces microphones that meet all the requirements of the precision measurement standards yet are robust and resistant to corrosion. These microphones are used in conjunction with the Norsonic range of preamplifiers that closely couple to them and ensure perfect matching to the associated instrument with minimum disturbance to the acoustic field. The preamplifiers have the necessary signal handling capability and low self noise to allow full use to be made of the wide dynamic range of the microphones.
Calibration
Calibration of all Norsonic microphones is directly traceable to National and International Standards with particular attention being paid in the design to ensuring long term stability. Each microphone is delivered with an individual certificate of calibration giving all the key information relating to its performance. This includes the nominal sensitivity and frequency response along with the environmental data that relates to the calibration.
Norsonic Calibration Laboratory is an international accreditated laboratory. This ensures that the quality of the measured values are at the highest possible level.
Free field microphones
All Norsonic microphones are Free-field types. A free field microphone is designed to measure the sound pressure in the sound field, compensating for the influence of the presence of the microphone in the sound field. In effect, the microphone measures the sound pressure as it existed before the microphone was introduced in the sound field, i.e. free field conditions. Applicable standard is IEC 61672 and the former IEC 60651. The free field microphone should be pointed towards the sound source at a 0° angle of incidence.
½” free-field, 50 mV/Pa sensitivity microphone. A general purpose microphone covering the frequency range from 3.15Hz to 20 kHz.
Correspond to the Class 1 of the sound level meter standard IEC 61672.
Specifications
Cartridge size: ½” inch
Main standard: IEC 61672 Class 1
Polarisation voltage: 200 volt
IEC 61094-4 Designation: WS2F
Nominal sensitivity: 50 mV/Pa
Frequency response: ±1dB 5 Hz – 10kHz, ±3dB 3.15 Hz – 20kHz
Maximum SPL (3% dist): 146 dB 20µPa
Self noise: 15 dB(A)
Capacitance: 18 pF
Temperature coeff. (250 Hz): <-0.005 dB°C
Max. temperature: 150 °C
Static pressure coeff. (250 Hz): -0.008 dB/kPa
Relative humidity coeff. (no condens.): Not measurable dB/%
Diameter: 13.2 mm
Length: 16.2 mm
Weight: 6 g
Nor1225S Trade-in microphone
Used, serviced, 1/2″ Free-field Condenser Microphone Nor1225 (only available against trade-in of malfunctioning Microphone Nor1225 without mechanical damage and less than 3 years old).
½” free-field, high sensitivity self-polarised microphone for use in applications where environmental or safety considerations do not permit the use of 200-volt polarisation supplies, or as a general IEC 61672 Class 1 microphone in sound level meters with no polarisation voltage.
Specifications
Cartridge size: ½” inch
Main standard: IEC 61672 Class 1
Polarisation voltage: 0 volt
IEC 61094-4 Designation: WS2F
Nominal sensitivity: 50 mV/Pa
Frequency response: ±1dB 5 Hz – 10k Hz, ±3dB 3,15 Hz – 20kHz
Maximum SPL (3% dist): 146 dB re. 20µPa
Self noise: 15 dB(A)
Capacitance: 14 pF
Temperature coeff. (250 Hz): <0.005 dB°C
Max. temperature: 120 °C
Static pressure coeff. (250 Hz): -0.008 dB/kPa
Relative humidity coeff. (no condens.): Not measurable dB/%
Diameter: 13.2 mm
Length: 16.2 mm
Weight: 6 g

½” free-field, high sensitivity, low cost self-polarised class 1 Microphone. Ideal for use in multi channels systems or other applicationos that requires a self polarised IEC 61672 class 1 microphone at low cost.
Specifications
Cartridge size: ½” inch
Main standard: IEC 61672 Class 1
Polarisation voltage: 0 volt
IEC 61094-4 Designation: WS2F
Nominal sensitivity: 50 mV/Pa
Frequency response: ±1dB 20-10k Hz, ±3dB 12.5 – 16k Hz
Maximum SPL (3% dist): 146 dB
Self noise: 16 dB(A)
Capacitance: 16 pF
Temperature coeff. (250 Hz): <0.005 dB°C
Max. temperature: 80 °C
Static pressure coeff. (250 Hz): -0.004 dB/kPa
Relative humidity coeff. (no condens.): -0.003 dB/%
Diameter: 13.2 mm
Length: 17.3 mm
Weight: 9 g
½” free-field, high sensitivity, low cost self-polarised class 2 microphone. Ideal for use in multi channels systems or other applications that requires a self polarised class 2 microphone accuracy.
Unlike most other low cost class 2 microphones it features a nickel membrane and a stainless steel housing, ensuring low sensitivity to environmental parameters such as temperature, static pressure and humidity.
Specifications
Cartridge size: ½” inch
Main standard: IEC 61672 Class 2
Polarisation voltage: 0 volt
IEC 61094-4 Designation: WS2F
Nominal sensitivity: 40 mV/Pa
Frequency response: ±3dB 20-10k Hz
Maximum SPL (3% dist): 146 dB
Self noise: 24 dB(A)
Capacitance: 13 pF
Temperature coeff. (250 Hz): <-0.01 dB°C
Max. temperature: 80 °C
Static pressure coeff.: ±0.03 dB/kPa
Relative humidity coeff. (no condens.): ±0.006 dB/%
Diameter: 13.2 mm
Length: 16.6 mm
Weight: 7 g
Norsonic offers a broad range of 1/2″ and 1/4″ preamplifiers.
Features
- High input impedance
- Broad frequency response
- Low noise
- Low output impedance for driving long microphones cable without any loss in performance.
- High dynamic range

This half-inch preamplifier is designed for calibration purposes using the insert voltage technique. The insert voltage technique is used for determine the open circuit voltage of a microphone cartridge. It is delivered with an integral LEMO style connector.
Specifications
Frequency range: 2Hz to 200kHz ±0.2dB
Input impedance: 20 Gohms, 0.2pF
Output impedance: 55 ohms @ 1kHz, CS: 20pF
Noise, A-weighted, CS 20pF: <3µV
Noise linear, CS 20pF: <6µV
Gain, typical: -0.15dB
Temperature, operation: -40 to +60°C
Temperature, storage: -40 to +85°C
Humidity, operation and storage: 0 to 95% RH
Current consumption (120V or ±60V): 2.5 mA
Current consumption (28V or ±15V): 0.7 mA
Dimensions:
Length: 77.5mm
Diameter: 12.7mm
Weight: 33g
CE classification, EMC: EN 50081-1, EN 50082-1
CE classification, safety: EN 61010-1, 1993 portable equipment pollution category 2 Hz to 1MHz ±0.5dB

¼” Microphone Preamplifier with insert voltage calibration and LEMO connector. This preamplifier is designed for calibration purposes using the insert voltage technique. The insert voltage technique is used for determine the open circuit voltage of a microphone cartridge.
Specifications
Frequency range: 2Hz to 200kHz ±0.2dB
Input impedance: 20 Gohms, 0.2pF
Output impedance: 55 ohms @ 1kHz, CS: 20pF
Noise, A-weighted, CS 20pF: <3µV
Noise linear, CS 20pF: <6µV
Gain, typical: -0.15dB
Temperature, operation: -40 to +60°C
Temperature, storage: -40 to +85°C
Humidity, operation and storage: 0 to 95% RH
Current consumption (120V or ±60V): 2.5 mA
Current consumption (28V or ±15V): 0.7 mA
Dimensions:
Length: 77.5 mm
Diameter: 6,35 mm (front part) 12.7 mm (connector part)
Weight: 27 g
CE classification, EMC: EMC: EN 50081-1, EN 50082-1
CE classification, safety: EN 61010-1, 1993 portable equipment pollution category 2

The Nor1207 is a low cost, general-purpose ICP®-preamplifier for 1/2” working standard prepolarized condenser microphones, designed for the most demanding use. It features a new design technology that increase the dynamic range to a value normally featured by traditional powered preamplifiers only. It is the first pattern evaluated ICP® preamplifier on the market, ensuring a high quality of the measurement in every environmental condition as specified in the class 1 requirements given in IEC-61672.
Nor1207 apply a male TNC-connector for connection to cable or instrument, while Nor1207/BNC comes with a BNC female connector.
Specification (Data given with 3mA supply current)
The preamplifier has to be supplied by a constant current in the range 3 – 20 mA. The output voltage will be a fixed DC (about 10 volt) plus the AC-coupled input voltage. Output AC-voltage swing is minimum +/-5 volt if not limited by the voltage for the current source.
Dynamic range: > 120dB
Input impedance: 20 Gohm, 2,5 pF (typical) for Nor1207/BNC 20 Gohm, 18 pF (typical) for Nor1207
Frequency response ± 0,1 dB: (10 Hz – 20 kHz)
Typical attenuation with microphone Nor1228 (18pF) due to capacitive loading: 1 dB for Nor1207/BNC and 6 dB for Nor1207
No signal DC out: 10 ± 2 volt
Output impedance: 35 ohm typical
Length incl. microphone Nor1228: 96 mm
Diameter:
Nor1207/BNC: 14,5 mm
Nor1207: 16 mm
Weight incl. microphone Nor1228: 50 g
Power consumption: 30 mW (dependent on supplied current)
EMC classification: As for sound level meter Nor131
Temperature for specified operation: -10°C to +50°C
Temperature for storing: -30°C to +70°C
Humidity for storing and operation: 0 – 90% RH
Microphone heating: No extra heating available

Self noise
Typical equivalent noise (level with a microphone with sensitivity 50mV/Pa and 18pF capacitance re. 20 µPa, e.g. Nor1228): 2 µV A-weighted (12 dB, Max 15 dB); 2,2 µV C-weighted (13 dB).
Max length of cable (100pF/m) with a microphone with sensitivity 50mV/Pa and 18pF capacitance (E.g. Nor1228):
Below 137 dB (re. 20 µPa): 30 m
Below 130 dB: 100 m
Below 120 dB (re. 20 µPa): 300 m
Connector type: Two versions available. Nor1207 with TNC connector and Nor1207/BNC with BNC jack.
ICP® is a registered trademark of PCB Piezotronics

The microphone preamplifier Nor1209 has been designed for general use with most 1/2″ condenser microphone of type WS2 or LS2 according to IEC 61094-4: Measurement microphones – Part 4: Specifications for working standard microphones.
Applications
- Sound level meters
- General purpose
- Laboratory and field measurements
Features
- Low noise
- High input impedance
- Wide dynamic range
- Wide frequency range
- Low output impedance
- System Check facility
- Large supply voltage range
- Detachable preamplifier cable