If you are running a signal cable over a long distance or have a spare current output pressure transmitter, it is possible to convert the output signal to a voltage type to make it compatible with voltage only input devices.
A typical current output is 2 wire 4 to 20 mA which is designed to be connected in a series with the power supply and other components included in the circuit. The pressure transmitter acts as a current source regulating the current at a particular pressure for a range of load impedances as long as there is sufficient supply voltage to power it.
If a load resistor is added to the circuit in series this will cause a voltage drop across the resistor which is directly proportional to the current being generated by the pressure transmitter. The potential of this voltage drop can be easily measured by connecting two voltmeter probes or an analog to digital converter to the circuit on either side of the resistor.
Featured 4-20ma current 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.
DMP320 0.5 msec Fast Response Pressure Sensor - High frequency response pressure sensor with a better than 0.5 millisecond response time and internal digital signal conditioning that samples readings at a rate of 10 kilohertz.
The voltage output generated by different values of load resistance on 4 to 20mA current loop are as follows:
| Load Resistor (Ω) | Min Volts | Max Volts |
|---|---|---|
| 50 | 0.2 | 1 |
| 100 | 0.4 | 2 |
| 150 | 0.6 | 3 |
| 200 | 0.8 | 4 |
| 250 | 1.0 | 5 |
| 300 | 1.2 | 6 |
| 350 | 1.4 | 7 |
| 400 | 1.6 | 8 |
| 450 | 1.8 | 9 |
| 500 | 2.0 | 10 |
| 550 | 2.2 | 11 |
| 600 | 2.4 | 12 |
| 650 | 2.6 | 13 |
| 700 | 2.8 | 14 |
| 750 | 3.0 | 15 |
| 800 | 3.2 | 16 |
| 850 | 3.4 | 17 |
| 900 | 3.6 | 18 |
| 950 | 3.8 | 19 |
| 1000 | 4.0 | 20 |
Alternatively use this tool to calculate the voltage drop from any 4-20mA current loop signal and load resistor value.
Featured voltage signal related products
Hydrostatic Liquid Level Voltage Output Pressure Transducers - Precision liquid level measurement with amplified voltage output hydrostatic pressure transducers. Ideal for industrial tanks, pump control, and volume calculation. 0-10V, 0-5V, and more.
Steam Pressure Transducers - Find steam pressure transducers with amplified voltage output and integral cooling features, designed for high-temperature steam in autoclaves, food processing, and power generation
Related Help Guides
- Choosing calibrator for pressure transmitters
- Advantages and Disadvantages of using a 4 to 20 mA Signal
- How to create a list of specification parameters for a pressure sensor
- How do you measure flow rate with a dp cell
- Why use 4-20mA and 3-15 psi rather than 0-20mA & 0-15psi
- Supply voltage and load resistance considerations for pressure transmitters
- How to Connect a 4-20mA Current Loop Pressure Transmitter
- 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
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
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