Correct Answer - Option 3 : two or three or four wires only
Telemetry system:
The quantity to be measured (called measurand) is detected and the output electrical signal is transmitted through the channel At receiving end the electrical signal is received and converted back into usable form as indicated, recorded or displayed by the end device.
Components:
A general electrical telemetry system has three basic components:
(i) Transmitter (ii) Receiver (iii) The channel interconnecting the first two
Classification:
- According to the physical connection between transmitter and receiver i.e. ‘channel’ which may consist of two, three or four wires.
- According to other channels such as telegraph, telephone, radio, microwave etc.
- According to characteristics of the signal i.e. voltage, current frequency, pulse.
- According to analog and digital signals.
Electrical positional system telemetering used for transmission of signal in two or three or four wires.
