The smart metering system is used for the remote measurement of measurands for a purpose of billing, and to process and transmit measurement results. Generation and transmission of measurement information by electric impulses has already been used at summarizing billing meters where the base meter is equipped with the impulses generator which directly or indirectly emits impulse to a master summarizing meter.
The application of more developed remote meter reading systems has intensified in the last decade of previous century. Today, most of distribution companies in Europe use remote meter reading systems to read the electricity consumption of industrial facilities on medium and high voltage level of distribution.
The smart metering system allows continuous reading and recording of many measurands, e.g. power quality and load curve, as well as early-stage failure detection, monitoring of the meter lid opening alarm (detection of unlicensed actions), detection of the opposite energy flow and many other appropriate signals. The advantage of these systems, besides the remote reading, is the possibility to control and set-up the parameters of the system without sending a human to the location. All mentioned induces the long-term reduction in financial expenses for the distribution system operator.
The most common communication systems for information and control signals transmission are GSM (Global System Mobile) and PLC (Power Line Carrier). PLC is prevailing lately due to its smaller cost and independence of the GSM operator. The PLC technology is mostly used to the closest distribution transformer station, from where information is carried to the rest of the system by optic cables.
The primary constraint on application of described systems is cost reduction and reaching reasonable cost effectiveness.

Different method to calculate uncertainty of antenna factor measurement is presented in this paper. This approach does not break the rules of standard uncertainty calculation approach, but reduces the entire uncertainty. It is obtained by performing the measurement with two reference dipole antennas and considering frequency dependent contributions of the uncertainty as well as the possible covariance between them.

Transfer measurements from the standard of direct voltage to the standard of alternative voltage is widely used in measurement and instrumentation. Well known method is based on the usage of thermo converter of voltage. There are some drawbacks of this method such as instability of error, hand mode of calibration and inertia of reproduction process. The new method of reproduction AC (AV) value proposed by usage of inertia’s properties of links of the parallel-resonance circuit to transfer measurements from the standard of direct current to the standard of alternative current. The paper illustrates the mechanism of action of AC-calibrator based on proposed method of reproduction, where AC signal is coming through L-inductor without its changes.

In this work, a novel wireless easy-to-use measuring system is presented to acquire the Lead I ECG signal and the heart rate. The system presents a novel application of the dual ground configuration to dry electrodes, to reduce their level of power line interference. With this, a good quality Lead I EGC signal can be obtained simply by placing the right and left hands on the dual electrodes. Heart rate is obtained with a novel algorithm based on the continuous wavelet transform (CWT), especially designed to avoid the electromyographic noise that can be present when acquiring signals in the hands. The algorithm presented has been tested in twelve subjects of different age and physical condition, obtaining a 99.7% of sensitivity and a 100 % of positive predictivity.

This paper describes a device based on a dsPIC (Digital Signal Peripheral Interface Controller) as a processing unit, capable of making impedance measurements at multiple frequencies. A DDS (Direct Digital Synthesizer) stimulates the measurement circuit composed by the reference impedance and the unknown impedance. The voltages across the impedances are amplified by programmable gain instrumentation amplifiers and then digitized by analog to digital converters. To measure the impedance, a seven-parameter sine-fitting algorithm is used to estimate the sine signals parameters. The dsPIC is connected through RS-232 or USB to a computer where the user can view the measurement results. The device also contains an LCD.