6.4 Measure
Sets the number of measurement channels, correction and other items.
| No. | Name | Description |
|---|---|---|
| 1 | Sub Channel Settings | Sets On/Off for sub channel (Sub1 to Sub3) display. |
| 2 | Frequency Weighting | Sets the frequency weighting for each channel. |
| 3 | Time Weighting | Sets the time weighting for each channel. |
| 4 | Windscreen Correction | Compensates for variations in sensitivity and frequency response due to attachment of the windscreen. Set to [On] when a windscreen is mounted to the device. |
| 5 | Diffuse S. F. Corr. | Compensates for variations in sensitivity and frequency response in diffuse sound fields for free fields. Set to [On] when measuring in a diffuse sound field. |
6.4.1 Sub Channel Settings
When set to [On], the sub channel sound level Lp is displayed on the measurement screen at the same time as the main channel.
The calculated values are also displayed for each channel.
Note
- Sub channel sound level data are also saved at the same time as the main channel and can be viewed on the [Recall] screen (“Loading the saved data”).
6.4.2 Frequency Weighting
Sets the frequency weighting for each channel.
| Item | Description |
|---|---|
| A | Sets A-weighting. A frequency filter that accounts for the relative loudness perceived by the human ear, and is selected when measuring general environmental noise. |
| C | Sets C-weighting. A frequency filter is applied that attenuates low-frequency range equal to or below 31.5 Hz and the high-frequency range equal to or above 8 kHz. In general, C-weighting may be used to reduce background noise such as wind noise for frequency analysis, or to measure loud sounds. |
| Z | Sets Z-weighting. A flat frequency filter is applied over the specified measurement frequency range. Select when measuring sound levels (physical quantity) over a wide band, or when performing frequency analysis of the measured sound. |
| G | Sets G-weighting. A frequency filter is applied that accounts for the relative loudness perceived by the human ear by infrasound. Select when evaluating the psychological and physiological effects of infrasound from 1 Hz to 20 Hz. |
| Z (HPF) | Sets Z-weighting and high-pass filter. |
| Z (LPF100Hz) | Sets Z-weighting and low-pass filter (cutoff frequency 100 Hz). |
| Z (LPF500Hz) | Sets Z-weighting and low-pass filter (cutoff frequency 500 Hz). |
6.4.3 Time Weighting
Sets the time weighting for each channel.
| Item | Description |
|---|---|
| F | Sets F (Fast). Select this when measuring general noise, especially fluctuating sound. This is usually used for measuring noise levels and sound levels. |
| S | Sets S (Slow). Select this to pick up sounds with little fluctuation or the average values of fluctuating sounds. This is used for measuring noise such as express trains and regular railway sounds, etc. It is also commonly used to measure low frequency sounds. |
| I | Sets I (Impulse). This responds to short, continuous sounds more quickly than F (fast) in the onset. |
| τ=10s | Sets 10s. S (Slow) is usually used to measure low frequency sound, but this setting with a larger time constant τ may be used in order to accurately capture the magnitude of infrasound of about 1 Hz. However, care must be taken because it becomes difficult to capture sounds that fluctuate in a short period of time. |
Note
- The device uses high-speed sampling (20.8 µs) data for the sound pressure waveforms for Leq and LE calculation, and so it is not affected by time weighting.
6.4.4 Windscreen Correction
Compensates for variations in sensitivity and frequency response due to attachment of the windscreen.
Set to [On] when a windscreen is mounted to the device.
Refer to the “Technical Guide” for details on windscreen correction.
| Item | Description |
|---|---|
| Off | Does not use windscreen correction. |
| WS-10 | Compensates for variations in sensitivity and frequency response due to attachment of Windscreen WS-10. Select this when attaching WS-10. |
| WS-15 | Compensates for variations in sensitivity and frequency response due to attachment of All-Weather Windscreen WS-15. Select this when attaching WS-15. |
| WS-16 | Compensates for variations in sensitivity and frequency response due to attachment of Rain-protection Windscreen WS-16. Select this when attaching WS-16. |
6.4.5 Diffuse S.F. Corr.
Compensates for variations in sensitivity and frequency response in diffuse sound fields for free fields.
Set to [On] when measuring in a diffuse sound field.
For details, refer to the “Technical Guide”.
| Item | Description |
|---|---|
| On | Uses diffuse sound field correction |
| Off | Does not use diffuse sound field correction |
When [On] is selected, [DF] is displayed at the top of the screen.