2 wire is used to distinguish electrical connections for measurement signals which use only two connections for carrying both the power supply and signal. The most common example is a 2 wire 4-20mA current loop output.
2 wire is also used to describe a resistive thermometer that is wired so that there is no compensation for errors caused by the connecting wire on each side of the resistive thermometer. Therefore a 2 wire connected resistive thermometer will be less accurate than 3 wire, or 4 wire compensation method.
Featured 4 to 20 ma current loop signal measurement products
DMP331 Precision Pressure Transmitter - Stainless steel pressure transmitter with ranges from 100mbar up to 40 bar gauge or absolute. Special options for ATEX , SIL2 and compound ranges.
200m deep well pump water level sensor, switch & display - Protect your deep well pump with thhis submersible level transmitter and wall mounted indicator and alarm. This system provides reliable water level monitoring and pump protection at depths of up to 200 meters.
Glossary of Measurement Signal technical terms
- 3 Wire
- 4 to 20 mA Current Loop Output Signal
- 4 Wire
- Amplified Voltage Output
- BFSG – Bonded Foil Strain Gauge
- Deadband
- FSO – Full Scale Output
- HART®
- mV/V – Millivolts per Volt Output Signal
- NC – Normally Closed
- NO – Normally Open
- Piezoresistive Strain Gauges
- Ratiometric
- Span
- Span Offset
- Span Sensitivity
- Square Root Extraction
- Threshold
- Totalizer
- Transducer
- Transmitter
- TSL – Terminal Straight Line
- TSS – Thermal Span or Sensitivity Shift
- Turndown Ratio
- USB
- Vented Cable
- Wheatstone Bridge Strain Gauge
- Zero Offset
- Zero Tare
Help from Measurement Signal resources
- How to get a 10 volt signal from a 4-20mA output pressure sensor
- What is the difference between zero offset and zero drift?
- Why use 4-20mA and 3-15 psi rather than 0-20mA & 0-15psi




