Uncertainty Analysis of Impedance Measurements in the Sampling Sensor Instrument

• Abstract:

  The algorithms based on digital signal processing for impedance components’ evaluation in circuits with sampling transducer have been analysed. It is supposed that the voltage and current are sampled synchronously to the fundamental frequency of the generated sinusoidal signal. Two fitting sine wave algorithms, which are based on the least mean square (LMS) technique, have been described. The first one reconstructs indirect measurement method. The second algorithm estimates the unknown impedance components by direct method. The uncertainty’s propagation by described algorithms can be analysed by means of covariance matrix. The elements of covariance matrix are dependent on the phase angles of the measurement signals. It is shown that those algorithms provide minimization of uncertainty for selected number of samples and phase angles. The influence’s simulations of quantization error of the AD converter and jitters of sampling time for described algorithms on uncertainty processing results have been carried out.
• Keywords:

  sampling sensor, impedance measurements, LMS method, fitting sine wave algorithms, covariance matrix, uncertainty analysis
• Download:

  IMEKO-TC7-2002-010.pdf
• DOI:

  _unreg_tc7-2002.010

Event details:

• IMEKO TC:

  TC7
• Event name:

  TC7 Symposium 2002
• Title:

  Symposium on New Developments in the Field of Measurement Science
• Place:

  Cracow, POLAND
• Time:

  25 June 2002 - 27 June 2002