SAMPLE AUTO-RANGING DATA ACQUISITION USING NATIONAL INSTRUMENTS SUPPORT

Cristian Zet, Marinel Temneanu, Cristian Fosalau, Mihai Cretu
Abstract:
In the process of data acquisition the analogic gain is usually determined by the peak value of the input signal. For all samples the quantization error is theoretically less than 1/2 LSB. However for samples having small value, the relative error due to the quantization is high, and it goes higher with the decreasing of the sample value. The relative measuring error can be reduced by dynamically setting the proper gain. This is usually achieved with a supplementary hardware arrangement. The solution proposed in this paper consists in a numeric algorithm, developed in LabView, which replaces the hardware. The idea is to measure the same signal with many channels, set up with different gains, and to rebuild the signals, choosing the samples measured with the maximum accuracy. Sample translation must be performed due to the inter-channel delay.
Keywords:
data acquisition, sample, quantization error
Download:
IMEKO-TC4-2001-141.pdf
DOI:
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Event details
IMEKO TC:
TC4
Event name:
TC4 Symposium 2001
Title:

11th IMEKO TC4 Symposium on Trends in Electrical Measurements and Instrumentation (together with 6th IMEKO TC4 Workshop on ADC Modelling and Testing)

Place:
Lisbon, PORTUGAL
Time:
13 September 2001 - 14 September 2001