Glossary

AI-1

Appendix I

GLOSSARY ABSORPTION WAVEMETER—An instrument used to measure audio frequencies. AMMETER—A meter used to measure current. BACK RESISTANCE—The larger resistance value observed when you are checking the forward resistance of a semiconductor. BAND PASS FILTER—A tuned circuit that passes only a specific frequency. BAND REJECT FILTER—A tuned circuit that does not pass a specified band of frequencies. BARRETTER—A type of bolometer characterized by an increase in resistance as the dissipated power rises. BEAT FREQUENCY—The difference between the oscillator frequency and the unknown audio frequency.

BEL—The unit that expresses the logarithmic ratio between the input and output of any given component, circuit, or system. BOLOMETER—A loading device that undergoes changes in resistance as changes in dissipated power occur. CAVITY WAVEMETER—An instrument used to measure microwave frequencies. CONTINUITY—An uninterrupted, complete path for current flow. CORRECTIVE MAINTENANCE—Used to isolate equipment failures. Includes replacement of defective parts to return equipment to proper performance. DAMPING—The process of smoothing oscillations of the meter pointer.

D’ARSONVAL METER MOVEMENT—The permanent-magnet moving coil movement used in most meters. dBm—An abbreviation used to represent power levels above or below a 1-milliwatt reference. DUMMY ANTENNA—See DUMMY LOAD. DUMMY LOAD—A resistor used to replace the normal load, which is specifically designed to have low reactance and possess the ability to dissipate required amounts of power. ELECTRODYNOMETER METER MOVEMENT—A meter movement using fixed field coils and a moving coil; usually used in wattmeters. EXTERNALLY EXCITED METER—A term used to describe meters that get their power from the circuit to which they are connected.

AI-2 FORWARD RESISTANCE—The smaller resistance value observed when you are checking the forward resistance of a semiconductor. FREQUENCY METER—An instrument used to measure the rate at which ac voltages are generated. GALVANOMETER—A meter used to measure small values of current by electromagnetic or electrodynamic means. GENERAL PURPOSE ELECTRONIC TEST EQUIPMENT (GPETE)—Test equipment that has the capability, without modification, to generate, modify, or measure a range of electronic functions required to test two or more equipments or systems of basically different designs.

INDUCTANCE BRIDGE—An ac bridge circuit used to measure an unknown value of inductance. MAINTENANCE—Work done to correct, reduce, or counteract wear, failure, and damage to equipment. MEASURE (Metrology Automated System for Uniform Recall and Reporting)—A Navy standardized system designed to provide the recall, scheduling, and documenting of test equipment into calibration facilities. MECHANICAL-ROTATION FREQUENCY—The speed in revolutions per minute of armatures in electric motors and engine-driven generators; blade speed in turbines.

MEGGER—A meter used to measure insulation resistance. METER MOVEMENT—The part of the meter that moves to indicate some electrical value. METER SHUNT—A resistor placed in parallel with the meter terminals; used to provide increased range capability. OHMMETER—A meter used to measure resistance. POWER FACTOR—An indication of the various losses of a capacitor, such as current leakage and dielectric absorption. PREVENTIVE MAINTENANCE—Consists of mechanical, electrical, and electronic checks; used to determine whether or not equipment is operating properly.

SCAT CODES—A four-digit subcategory code used to identify the functional measurement parameters that can be satisfied by any one of many pieces of test equipment. SELF-EXCITED METER—A term used to describe meters that operate from their own power sources. SENSITIVITY—(1) For an ammeter, the amount of current that will cause full-scale deflection of the meter. (2) For a voltmeter, the ratio of the voltmeter resistance divided by the full-scale reading of the meter; expressed in ohms per volt. SCLSIS (Ship Configuration and Logistics Support Information System)—This encompasses the automated data processing system and all practices and procedures used for identification and status accounting of ship's configuration, logistics, technical data reviews, and equipment configuration audits.

SHORT CIRCUIT—An unintentional current path between two components in a circuit or between a component and ground; usually caused by a circuit malfunction. AI-3 SPECIAL PURPOSE ELECTRONIC TEST EQUIPMENT (SPETE)—Test equipment that is specifically designed to generate, modify, or measure a range of electronic functions of a specific or peculiar nature on a single system or equipment. STROBOSCOPE—An instrument that allows viewing of rotating or reciprocating objects by producing the optical effect of a slowing down or stopping motion.

SYMPTOM ELABORATION—Using built-in indicating instruments or other aids to define an equipment malfunction. SYMPTOM RECOGNITION—Recognition of a situation in equipment operation that is not normal. TACHOMETER—An instrument that measures the rate at which a shaft is turning. TEST EQUIPMENT INDEX—The Navy guide used to assist in identifying portable electrical/electronic test equipment required for support of prime electrical/electronic, IC, weapons, and reactor instrumentation systems. TEST POINTS—Locations in equipment that are accessible to the technician's probes where operating voltages or signals can be monitored.

THERMISTOR—A type of bolometer characterized by a decrease in resistance as the dissipated power increases. TROUBLESHOOTING—A procedure used to evaluate equipment performance and repair equipment when it fails to operate properly. TUNED CIRCUIT—A circuit that is used as a filter which passes or rejects specific frequencies. VOLTMETER—A meter that is used to measure voltage. WATT—The unit of electrical power that is the product of voltage and current. WATTMETER—An electrodynamometer type meter used to measure electrical power.

WAVEFORM ANALYSIS—Observation of displays of voltage and current variations with respect to time or by harmonic analysis of complex signals. WAVEMETER—Calibrated resonant circuits that are used to measure frequency. WHEATSTONE BRIDGE—An ac bridge circuit used to measure unknown values of resistance, inductance, or capacitance.