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.
4-20mA signal related products
Pressure Indicator Transmitters
Vacuum Pressure Transmitters
800 kPa g range 4-20mA output freshwater pressure sensor for agricultural pump use
200m deep well pump water level sensor, switch & display
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.
4-20mA signal related products
4-20mA Output Hydrostatic Level Transmitters & Sensors
Differential Pressure Transmitters
Low Differential Pressure Transmitters
Gas supply 100 mbar static pressure transmitter for boiler room
Related Help Guides
- How to get a 10 volt signal from a 4-20mA output pressure sensor
- Transforming a 2 wire Current Loop into a Voltage Output Signal
- How do you measure flow rate with a dp cell
- 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
- 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®
- Isolation Diaphragm
- Square Root Extraction
- Stainless Steel Pressure Sensors
- Transmitter
- Turndown Ratio
Related Online Tools
- 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
- Pressure Transmitter 4-20mA Current Output Calculator
- 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