test equipment for an FRO lecture

1. Test Equipment

2. overview Measuring things General purpose electronic measuring equipment Radio test equipment Other equipment Standards

3. Types of measurement equipment Electronic Voltage Current Resistance Radio SWR meter Types Digital Analogue

4. Measurement Systems Effect the system under test (Loading problem) Voltmeters takes current Ammeters drop voltage Resistance of the measurement device Accuracy Imperfections in the test equipment Scales

5. Volt meters Analogue meter Magnetic coil in a magnetic field Spring Digital meter A-to-D converter

6. Voltmeter Measure in parallel High resistance in the meter

7. Voltmeter Loading problem 25 V each resistor Meter internal voltage = 1 MW 1/R = 1/1MW + 1/1MW = 500 kW I = 50V/1500 kW = 33 mA V = 16.6 V

8. Voltmeter Accuracy 99% accuracy 95% accuracy

9. Voltmeter Ranges Shunt circuits

10. Ammeters Wired in series Low internal resistance Ranges Shunt circuit

11. Ohm meters Ammeter + resister and battery Using in circuit: Turn off power Isolate the component

12. Multi-meter Voltage, ammeter and ohm meter in one.

13. Ammeters Shut circuit

14. Radio Test Equipment Antenna output

15. Radio Test Equipment

16. Other equipments Oscilloscope Signal Generator

17. Standards National standards agency International standard agency

18. Standards Weston cell Anode of cadmium and mercury Cathode of mercury cadmium sulfateoctahydrate 1.018638 V

19. Standards

20. Questions?