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
High Temperature Pressure Transmitters - High temperature pressure transmitters with a 4-20mA output, tolerant to high temperature applications such as steam, food processing & engine monitoring.
DMD331 Compact Differential Liquid Pressure Sensor - Wet wet differential pressure sensor with a high overpressure rating on both positive and negative pressure side for protection against damage.
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
100 Pa bi-directional range differential air pressure transmitter - Bi-directional low range 4 to 20 milliamp differential pressure transmitter covering an air pressure range from -100 to +100 pascals, for cleanrooms, isolation rooms, and filter monitoring.
XMPi Process Plant Gauge and Absolute Pressure Transmitter - Process transmitter for measuring vacuum, steam, food, pharmaceutical, oil, gas and other pressure readings necessary for the monitoring and control of bulk production processes.
Related Help Guides
- Supply voltage and load resistance considerations for pressure transmitters
- How to Connect a 4-20mA Current Loop Pressure Transmitter
- 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