Controls: Calibration Menu >> User Units >> User Line
Macro: UserFactor

If the selected User Line does not use a .CAL file, this control allows you to specify the conversion factor that Daqarta must apply to the raw voltage values in order to display them in your chosen User Units.

The Units/Volt value is usually supplied as a calibration factor when you purchase a transducer. It may be supplied as Volts/Unit, in which case you need to enter the reciprocal of the value here.

For example, a force transducer may be calibrated such that when a Newton of force is applied, the transducer output is 1.234 mV. The value you should enter is thus 1 / 0.001234 or 810.3728 Newtons/Volt.

If the value to be entered is very large or small, use a size prefix directly in the value entry, never in the name field. Daqarta will always show the value with a convenient prefix, such as '1.00000p' for 1 pico-unit. Do not enter 1.000 here with a 'p' prefix in the name field.

When Y-log Spectrum mode is active, this control will change to dB relative to 1 Unit/Volt (indicated as dB:Units/V). For example, 2.0000 Units/V will become 6.0206 dB:Units/V. You may find this mode more convenient for entering microphone or speaker sensitivities.

If the line uses a .CAL file, the Units/Volt control will be disabled but will show the baseline value from the file. This is the value that will be used with waveform and linear Spectrum displays, which don't support the frequency-dependent calibration that Y-log Spectrum does. In those modes, the trace or cursor readout values are only approximate.

Macro Notes:

If the relevant User Line dialog is open, UserFactor=1.234 will set 1.234 User Units per Volt.

However, it is usually more useful for a macro to change User Line controls directly, without the dialog open. This requires that you use Uxx. prefixes before the macro command to specify which line the macro refers to, as in U0L.UserFactor=1.234.

U0L. through U7R. specify Input lines 0-7 and the Left or Right channel of each.

If your card has only Master Input lines, UIL. or UIR. prefixes will specify them here.

If your card has only Master Output lines, specify them with UOL. or UOR. prefixes.

Otherwise, UWL. and UWR. prefixes specify Wave Out lines.

If a data file is open, UIL. and UIR. prefixes specify Left and Right Input lines, while UOL. and UOR. specify Output lines.

See also User Units dialog, User Line Dialog

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