Measurement microphones

There are different types of measurement microphones, which differ in their design and attributes. Here are some of the most common types:

1. Condenser microphones: Condenser microphones use a condenser capsule to convert the sound pressure into electrical signals. They offer high sensitivity and accuracy, but are sensitive to moisture and require phantom power.

2. Electret microphones: These microphones use a fixed electret foil to capture sound signals. They are less expensive than condenser microphones and do not require phantom power. They are well suited for use in mobile devices.

3. Dynamic microphones: Dynamic microphones use a coil and a diaphragm to capture sound signals. They are robust, durable and can handle high sound pressures. They are well suited for live use and loud environments.

4. Tape microphones: Ribbon microphones use a ribbon as a transducer to convert sound into electrical signals. They offer high sensitivity and accuracy, but are less robust than dynamic microphones.

5. Carbon microphones: Carbon microphones are an older technology and use a carbon granulate capsule to capture sound. They are rarely used today as they offer lower sound quality and sensitivity.

6. Lavalier microphones: Lavalier microphones are small and are often attached to clothing or the body. They are well suited for presentations or television appearances, but may not offer the same sound quality as larger microphones.

The various types of measurement microphones therefore differ in their design, sensitivity, sound quality and areas of application. The choice of the right microphone depends on the specific requirements of the measurement or application.

Measurement microphones are special microphones that are generally used for precise and accurate measurements of sound. They work according to the principle of pressure gradient measurement.

The principle of pressure gradient measurement is based on the fact that sound waves influence both the air pressure and the direction of sound. The measuring microphone consists of a capsule with a thin membrane and a resonating body behind it. The diaphragm reacts to the sound waves and generates a movement that is proportional to the sound pressure. The resonator amplifies this movement.

Inside the measuring microphone there is a pressure gradient receiver that measures the direction of the sound. This receiver consists of a hole in the membrane that is connected to a fine bore. When sound waves hit the diaphragm, a pressure gradient is created between the hole and the bore. This pressure gradient is converted into an electrical voltage, which can then be measured.

By combining the sound pressure and the pressure gradient, the measuring microphone can measure both the sound pressure and the sound direction. This enables precise detection of sound in various environments and applications, such as room acoustics, noise measurement or sound level measurement.

In order to provide precise and accurate measurement results, measurement microphones must have the following attributes:

1. Calibration: The measurement microphone should be calibrated before use to ensure that it provides correct results. Calibration should be repeated regularly to maintain accuracy.

2. Linearity: The microphone should have a linear response to the sound pressure in order not to falsify the measurements. A non-linear response leads to distortion of the measurement results.

3. Frequency response: The measurement microphone should have a frequency response that is as uniform as possible in order to capture all frequencies in the measurement range equally well. Any deviations in the frequency response should be taken into account in the calibration.

4. Sensitivity: The sensitivity of the measuring microphone should be known and taken into account in the measurements. Too low a sensitivity can lead to inaccurate measurements, while too high a sensitivity can lead to overmodulation and distortion.

5. Directional characteristic: Depending on the application, different directional characteristics may be required, such as omnidirectional, cardioid or figure-of-eight. The directional characteristic influences which sound sources the microphone picks up and how well it suppresses ambient noise.

6. Interference immunity: The measuring microphone should be as insensitive as possible to external interference such as electromagnetic fields, structure-borne noise or mechanical vibrations in order to ensure accurate measurement results.

7. Dynamic range: The measurement microphone should have a sufficiently wide dynamic range to capture both quiet and loud sound levels without causing clipping or distortion.

8. Low distortion: The microphone should work with as little distortion as possible so as not to falsify the measurement results. Distortions can be caused by non-linearities or overmodulation, for example.

9. Robustness: The measurement microphone should be robust and durable in order to withstand the demands of measurement operation. It should be protected against external influences such as moisture, dust or mechanical stress.

10. Calibration options: To ensure long-term accuracy, the measuring microphone should be able to be calibrated regularly. This can be done either by the manufacturer itself or by external calibration laboratories.

Measurement microphones are used in various areas to record and analyze acoustic signals. Here are some applications and areas of use for measurement microphones:

1. Acoustic measurement technology: Measurement microphones are used to measure sound levels, frequency spectra and other acoustic parameters. This is important, for example, in room acoustics, noise measurement, noise abatement and sound quality assessment.

2. Audio recording and playback: Measuring microphones are used in recording technology to produce high-quality audio recordings. They are used in recording studios, radio and television studios and for live performances.

3. Communication technology: Measurement microphones are used in telecommunications to record and transmit voice signals in telephones, headsets and other communication devices.

4. Automotive: Measurement microphones are used in the automotive industry to measure and analyze the noise and vibration behavior of vehicles. This is important for improving driver comfort and reducing noise in the vehicle interior.

5. Environmental monitoring: Measurement microphones are used to monitor ambient noise and to comply with noise protection regulations. They are used in cities, industrial plants and other environments to measure and monitor noise levels.

6. Medical diagnostics: Measurement microphones are used in medical diagnostics to record and analyze body sounds such as heartbeats, breathing sounds or bowel sounds. This helps doctors to diagnose diseases and conditions.

7. Research and development: Measurement microphones are used in many scientific fields to research and analyze acoustic phenomena. This includes fields such as physics, engineering, psychology and musicology.

This list is not exhaustive and there are certainly many more applications for measuring microphones in various industries and areas.

The selection and placement of measurement microphones in different measurement environments is influenced by several factors:

1. Type of measurement: Depending on the type of measurement, e.g. in acoustics, sound engineering or room acoustics, different microphone types are required. For example, condenser microphones are often used for high-precision measurements, while dynamic microphones are more robust and better suited to noisy environments.

2. Frequency range: The frequency range that a microphone can capture is an important factor in the selection process. Depending on the desired measurement, microphones with different frequency ranges must be used.

3. Directional characteristic: The directional characteristic of a microphone determines the direction from which it picks up sound. Depending on the measuring environment and the desired sound detection, microphones with different directional characteristics must be used, e.g. omnidirectional, cardioid or figure-of-eight characteristic.

4. Ambient noise: In noisy environments, microphones with high noise suppression must be used to capture the desired sound and minimize background noise.

5. Placement: The exact positioning of the microphones is crucial for the accuracy of the measurement. Microphones should be placed close to the sound source to ensure that the sound is recorded as accurately as possible. Depending on the measuring environment, this may require mounting on a tripod, on the wall or on other suitable surfaces.

6. Reflections and room acoustics: In rooms with poor acoustics or strong reflections, microphones may need to be strategically placed to minimize unwanted reflections and capture the desired sound.

7. Calibration: Microphones must be calibrated regularly to ensure that they accurately capture the desired measurements. Calibration should be carried out in accordance with the manufacturer's specifications and the requirements of the measuring environment.

These factors influence the selection and placement of measurement microphones and are important to ensure accurate and reliable measurements in different environments.

When calibrating measurement microphones, various special features must be taken into account:

1. Frequency response: Measurement microphones usually have a specific frequency range in which they operate linearly. It is important that the frequency response of the microphone is taken into account during calibration to ensure accurate measurements.

2. Sound pressure level: Measurement microphones have a maximum sound pressure level limit that they can withstand without distortion occurring. During calibration, care should be taken to ensure that the sound pressure level is within the permissible range.

3. Ambient conditions: Calibration should be carried out in a controlled environment to ensure the accuracy of the measurements. This includes controlling the room temperature and humidity and avoiding air currents.

4. Reaction of reflections: Microphones can be affected by reflections of sound waves bouncing off surfaces in the environment. Reflections should therefore be minimized during calibration to ensure accurate measurements.

5. Calibration standards: Measurement microphones should be calibrated regularly at accredited calibration laboratories to ensure that they comply with the applicable standards. Calibration should be carried out in accordance with the guidelines and standards of the International Organization for Standardization (ISO) or other relevant organizations.

6. Calibration data: After calibration, the measurement microphones should be provided with the corresponding calibration data. This data contains information about the frequency response, sensitivity and other important parameters of the microphone and serves as a reference for future measurements.

It is important to take these special features into account when calibrating measurement microphones in order to obtain accurate and reliable measurements.

Measurement microphones are used in industry and research to carry out acoustic measurements. They are used to detect sound waves and convert them into electrical signals, which can then be analyzed and evaluated. They can be used in various areas, for example in environmental acoustics, room acoustics, vehicle acoustics or noise measurement.

In industry, measurement microphones can be used to measure and analyze the noise generated by machines and systems. This can help to minimize noise pollution for employees and comply with statutory noise protection regulations. They can also be used for quality assurance to check the acoustic attributes of products, for example when testing loudspeakers or other devices.

In research, measurement microphones are often used to analyze sound sources and characterize sound fields. They can be used, for example, to investigate sound propagation in different environments or to research the sound radiation of structures. Measurement microphones are also used in psychoacoustics to investigate the perception of sound and human hearing performance.

The measurement microphones are usually combined with appropriate measurement technology and software to record, analyze and interpret the acoustic signals. Various parameters such as sound pressure level, frequency spectrum, time response or directional characteristic are measured and evaluated. The results can then be used to optimize products, processes or environments.

There are several current developments and trends in the field of measurement microphone technology:

1. Miniaturization: There is a trend towards the development of ever smaller measuring microphones. This allows it to be used in areas where conventional microphones are too large or impractical.

2. Wireless communication: Measurement microphones are increasingly being equipped with wireless communication technology to facilitate the transmission of measurement data. This enables flexible and convenient data acquisition in real time.

3. Integrated sensors: New measuring microphones have integrated sensors such as accelerometers and temperature sensors. These extended functions enable more precise measurement and better analysis of environmental conditions.

4. Digital signal processing: Modern measurement microphones use advanced digital signal processing techniques to reduce background noise and improve signal quality. This enables more precise and reliable measurements.

5. Combination with other technical devices: Measurement microphones are increasingly being combined with other technical devices such as smartphones or tablets. This enables easy integration into existing measurement systems and convenient data acquisition and analysis.

6. Calibration and standards: The development of accurate calibration standards and norms for measurement microphones is an important trend. This ensures the comparability and accuracy of the measurement results and facilitates the exchange of data between different systems.

These developments and trends help to improve the performance and versatility of measurement microphones and open up new application possibilities in various industries such as acoustics, medicine, environmental monitoring and the automotive industry.