To find the AI Gain Amplitude Accuracy, AI Offset and AI Flatness refer to the NI 4461/4462 Specifications.
For a 1 kHz sine wave with an amplitude of 10V, the following values apply:
AI Gain Amplitude Accuracy = ±0.03 dB max
AI Offset (with no Gain applied) = ±0.7 mV max
AI Flatness (with no Gain applied) = ±0.003 dB typical
Gain Error is calculated based on this Gain Amplitude Accuracy of a 1kHz input tone.
Gain Amplitude Accuracy = ±0.03 dB max
Gain Amplitude Accuracy(dB) = 20 log (1 + (Gain Error(%)/100))
±0.03 dB = 20 log (1 + (Gain Error(%)/100))
Gain Error(%) = 0.3460
Gain Error(V) = Input Voltage x Gain Error(%) = 10 x 0.003460 = 34.60 mV
Where the Input Voltage refers to the voltage range the device is configured for.
Flatness is converted to voltage in an identical manner.
Flatness = ±0.003 dB max
Flatness(dB) = 20 log (1 + (Flatness(%)/100))
±0.003 dB = 20 log (1 + (Flatness(%)/100))
Flatness(%) = 0.0345
Flatness(V) = Input Voltage x Flatness(%) = 10 x 0.000345 = 3.45 mV
From these two calculation the total AI Accuracy is calculated as follows:
AI Accuracy = AI Gain + AI Offset + AI Flatness
AI Accuracy = 34.60 mV + 0.7 mV + 3.45 mV
AI Accuracy = ±38.75 mV