Source:http://linkedlifedata.com/resource/umls/id/C3204124
UMD: Measuring instruments designed to measure electric resistance, a measure of a substance opposition to conducting electric charges when a voltage is applied. This parameter is frequently represented by an uppercase omega and typically measured in ohms. Resistance meters (ohmmeters) may consist of electromechanical or electronic instruments with appropriate leads. Practical instruments may measure in ohm, fractions of ohm (e.g., milliohm) or multiples of ohm (kilo- or mega ohm, frequently called megohmmeters). Dedicated resistance meters are used to measure solid material and/or liquids; some are incorporated in testers used in the inspection and/or maintenance of medical devices and other healthcare facility equipment.