Ammeter to be measured with both polarities, common in scientific and industrial equipment. Zero-center ammeters are also commonly placed in series with a battery. In this application, the charging of the battery deflects the needle to one side of the scale (commonly, the right side) and the discharging of the battery deflects the needle to the other side. A special type of zero-center ammeter for testing high currents in cars and trucks has a pivoted bar magnet that moves the pointer, and a fixed bar magnet to keep the pointer centered with no current. The magnetic field around the wire carrying
Electrical cardiometry temporarily stored in the ascending aorta contributes to a decrease in bioimpedance (or an increase in conductity of the thorax). The underlying model never proved accurate in patients with small cardiac outputs, hence it was never U.S. FDA approved for use in children or neonates. The electrical and impedance signals are processed, and then utilized to measure and calculate hemodynamic parameters such as cardiac output, stroke volume, systemic vascular resistance, thoracic fluid index, ICON (index of contractility), and systolic time ratio. Electrical cardiometry Electrical cardiometry is a method based on the model of "Electrical Velocimetry", and non-invasively measures stroke volume