Sampling Parameters

The above toolbar contains (from left to right):

Sampling Frequency, Sampling Channels, Sampling Bit Resolution, and Record Length Per Scan.

Sampling Parameters together with the Trigger Parameters determine how the data are sampled and collected. The sampling capability is fully dependent on the sound card. Once the sampling parameter is specified and "Run" button is clicked, it will attempt to start sampling using the specified sampling parameters. An error message will pop up if the specified sampling parameters are not supported by the sound card. Note that some sound card may not generate an error message even if the sampling frequency specified exceeds its limit. Please check your sound card manual before you use a sampling frequency greater than 44100 Hz, otherwise measurement error may be introduced.

Sampling Frequency

The following sampling frequencies can be selected: 2000 Hz, 4000 Hz, 8000 Hz, 11025 Hz, 22050 Hz, 44100 Hz, 48000 Hz, 96000 Hz, 192000 Hz. In addition, you can enter a frequency value directly.

Sampling Channels

Two options are available:

• A: Only Channel A is sampled.
• A&B: Both Channel A and Channel B are sampled.

Sampling Bit Resolution

Three options are available: 8Bit, 16Bit, 24Bit.

Record Length Per Scan

Record Length Per Scan (or Per Frame) determines how many points will be recorded per scan for each channel. Normally you do not need to specify the Record Length directly as it is implicitly determined by the Scan Time and the Sampling Frequency (Record Length = Scan Time × Sampling Frequency). When you change the Scan Time or Sampling Frequency, the Record Length will be automatically updated accordingly. Under some circumstance, you may want to explicitly specify the record length, for example, you may want the Record Length to be an integer multiple of 10 or an exponent of 2. Then you can either select or enter the Record Length you want directly. The scan time will then be automatically updated accordingly so that all data points can be accommodated in one scan.

There are 8 options available for you to select: 50, 100, 200, 500, 1000, 2000, 5000, 10000.

Alternatively, you can enter any number for the Record Length as long as the scan time is less than 500 s and the computer memory allows.

Changing Record Length directly is disabled at the very beginning in order to avoid confusion to beginners. It can be enabled via [Setting]>[Display]>[Enable Record Length change via "Point" in Sampling Parameter Toolbar].