Time delay estimation is an important research question having many applications in a range of technologies. Measurement of a two‐phase flow in a pipeline or an open channel using radioisotopes is an example of such application. For instance, the determination of velocity of dispersed phase in that case is based on estimation of the time delay between two stochastic signals provided by scintillation probes. The proper analysis of such signals, usually in presence of noise, requires the use of advanced statistical signal processing. In this paper, the simulation studies of time delay estimation were carried out with the use of the following differential methods: average magnitude difference function, and average square difference function and proposed combined methods comprising the above‐mentioned differential and cross‐correlation functions are presented. Attached simulations have been carried out for models of stochastic signals corresponding to the signals obtained in gamma‐ray absorption measurements of gas‐liquid flow in a horizontal pipeline. The standard uncertainties of time delay estimations have been determined for each of the methods. Improved metrological properties have been stated in the combined methods in comparison with the classical cross‐correlation procedure.

EPJ Web of Conferences, open-access proceedings in physics and astronomy

EPJ Web of Conferences, open-access proceedings in physics and astronomy

The article presents the hardware and software configuration of the developed multi-channel temperature measurement system as well as calibration procedures and measurement results verifying the properties of measurement channels. The system has been developed and dedicated primarily for measuring the temperature distribution in a laboratory model simulating underground power lines. With the adopted configuration of the analog part of each measurement channel, the main functions in the system developed as a virtual instrument are performed in its software. The instrument input circuits contain NTC (negative temperature coefficient) thermistors used as temperature sensors. The resistance of each of the thermistors connected in the voltage divider circuits is converted into a voltage. The obtained voltages in the measurement channels, after analog-to-digital conversion (ADC), are processed in subsequent operations in the instrument’s software. In addition to the basic function of the device, which is the multi-channel temperature measurement, the operations of identifying the characteristics of the thermistors used and calibrating each of the individual measurement channels are performed. The article contains sample results of the calibration of measurement channels and temperature verification measurements used to evaluate the properties of the developed system. The obtained inaccuracy of the temperature measurement in each of the channels is less than 0.4 °C.