A 4-20mA current signal has become very popular for many applications beyond it’s original intended purpose in the process industry. It is now used throughout industry as the preferred measurement and control signal for many different types of systems.
Despite the popularity of the 4-20mA signal, it is not the best solution for every application and here are some of the ‘for’ and ‘against’ reasons for determining whether it is the right type of signal for your application.
Featured 4-20ma signal related products
16 bar, 200°C steam pressure transmitter and gauge - Combined pressure transmitter and indicator in one package with the option for use with high temperature media such as steam at 200°C
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.
Advantages
- It can be run over long distances with minimal signal losses compared to voltage type signals
- A varying current loop load impedance or supply voltage will not significantly affect the signal as long as it does not exceed recommended component limits
- Rugged signal with low electromagnetic susceptibility
- Saves on cable wire because it only needs 2 wires to function
- Live zero reading verifies sensor is electrically functional
Disadvantages
- High power consumption compared to other analogue signal types
- Elevated output at zero reading
- Supply not isolated from output
- Increasing circuit load resistance, will reduce the supply voltage available to power the transmitter that is generating the 4-20mA signal.
Featured 4-20ma signal related products
Differential Pressure Transmitters - Differential pressure transmitters for measuring the DP of fluids and gases across particle filters and along a length of pipe to monitor flow.
DMP343 Low Range Pneumatic Pressure Sensor - DMP343 pneumatic pressure sensor for measuring very low range pressures on pneumatic control systems, heating, ventilation and air conditioning systems (HVAC) .
Related Help Guides
- How to Connect a 4-20mA Current Loop Pressure Transmitter
- Supply voltage and load resistance considerations for pressure transmitters
- Why use 4-20mA and 3-15 psi rather than 0-20mA & 0-15psi
- Transforming a 2 wire Current Loop into a Voltage Output Signal
- How do you measure flow rate with a dp cell
- How to get a 10 volt signal from a 4-20mA output pressure sensor
- What is the difference between a pressure transducer and a transmitter
- Choosing calibrator for pressure transmitters
- How to create a list of specification parameters for a pressure sensor
Related Technical Terms
- 2 Wire
- 4 to 20 mA Current Loop Output Signal
- HART®
- Square Root Extraction
- Stainless Steel Pressure Sensors
- Transmitter
- Turndown Ratio
Related Online Tools
- Pressure Transmitter 4-20mA Current Output Calculator
- Flow Transmitter 4-20mA Current Output Calculator
- DP Flow Transmitter Output Calculator
- 4-20mA Signal to Measurement Reading Converter
- SqRt Extraction 4-20mA Signal to Measurement Reading Converter
- Temperature Transmitter 4-20mA Current Output Calculator
- Liquid Level Transmitter 4-20mA Current Output Calculator
- 4 to 20 mA Supply, Load, Shunt and Signal Calculator