Lowers Recommended Lead-Level Limits in Children. For the first time in 20 years, federal health authorities have lowered the recommended limit for lead exposure in young children, which they say could add 200,000 children to those believed to have unsafe lead levels in their blood.
Electrical Units of Measure. The standard SI units used for the measurement of voltage, current and resistance are the Volt [ V ], Ampere [ A ] and Ohm [ Ï ] respectively.
Principle of the measurement. The electrical conductivity of a solution of an electrolyte is measured by determining the resistance of the solution between two flat or cylindrical electrodes separated by a fixed distance. An alternating voltage is used in order to avoid electrolysis. The resistance is measured by a conductivity meter.