
Q1: Can the 4-20mA+RS485 pressure transmitter output at the same time when working?
A1: The pressure transmitter can have two output signals at the same time. But it is recommended to output one signal when using it. When two signals are used at the same time, there will be a loss of accuracy in the 4-20mA signal.
Q2: Why are analog pressure transmitters often equipped with 4-20mA output instead of 0-10V or 0-20mA?
A2:
① The anti-interference ability of current output(4-20mA and 0-20mA) is obviously better than that of the voltage signal during transmission. 0-10V voltage signals are susceptible to external electromagnetic interference. When the pressure transducer is farther from the display device, the cable length will be longer. The certain resistance of the cable can cause a voltage loss. However, the current signal will not be affected by the resistance value, but is only related to the load capacity.
② When 0-20mA pressure sensors output 0mA, you can't determine whether a minimum pressure output or a cable disconnection fault.
Q3: How to change the pressure transmitter from analog output to other types output?
A3: You need to change the circuit board.
Q4: How to solve the large fluctuations of the output signal?
A4: You need to confirm the following factors causing unstable output through the elimination method:
① Check whether the power supply is stable.
② Check the site environment.
③ Check if there is a product problem; you can use the spare product for verification.
④ Check the pressure system for interference by exchange and comparison tests of multiple on-site measurement points.
Q5: What's the longest transmission distance for different output cable pressure transmitters?
A5:
| Output Signal | Transmission Distance |
| Current Output | 1000m |
| Voltage Output | 50m |
| RS485 Output | 1200m |
| RS232 Output | 10m |
| I²C Output | Recommended: 2m (Theoretical: 5m) |
Q6: Can the I²C pressure transmitter be converted from pressure data to level data?
A6: The output signals of I²C pressure sensors are hexadecimal numbers. The pressure value can be converted into a level or other unit data in the PC software.
The FAQs above illustrate that a pressure transmitter output signal is far more than a simple current or voltage reading—it is the critical bridge connecting the physical process to the digital control system. From the classic 4-20mA analog signal to the digital pressure transmitters, each output type serves specific application needs, system architectures, and future maintenance considerations.
As a leading manufacturer of pressure transmitters, we offer a comprehensive output portfolio. For any consulting, please contact our technical sales team to identify the optimal output configuration for your specific application.
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