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?