How DR3702 Digital Pressure Gauge Solved EMI Noise Issues
Why Our $50,000 Production Run Was Ruined by a $200 Sensor
The hydraulic press was cycling slower. The gauge showed normal pressure, but every part was out of spec. We traced this issue back to a faulty pressure sensor that couldn’t handle the 400°C environment inside our extruder. This failure cost us an entire shift of production and $50,000 in scrap material.
The Hidden Cost of 4-20mA Loop Failures in High-EMI Environments
A 4-20mA loop is a current source—ideal for long cable runs. However, these cables act as antennas, picking up EMI and causing drift at the PLC input card. Every time we replaced the transmitter with another model, it failed due to this same issue. The root cause was common-mode noise, not the sensor itself. In fact, the 4-20mA signal is susceptible to noise because it relies on a single-ended voltage measurement across a resistor. This means any induced voltage from nearby motors or variable frequency drives corrupts the reading.
How DR3702 RS485 Digital Pressure Gauge Solved Our Common-Mode Noise Problem
The investigation led us to the DR3702 digital pressure gauge. Its RS485 differential signaling rejects common-mode noise entirely, ensuring clean data transmission even over long distances. We installed two sensors and verified that they provided consistent readings under various conditions. Moreover, the DR3702 offers both 4-20mA and RS485 outputs, giving us flexibility for future upgrades. The LCD display with backlight and 5-digit readout made troubleshooting straightforward.
Why We Reduced Downtime by 90% and Eliminated Recalls
With these new transmitters in place, we reduced production downtime by 90% and improved product quality to meet industry standards. No more false alarms or costly recalls. The DR3702’s durable housing withstands the harsh industrial environment, and its nonlinear correction ensures accuracy across the entire pressure range. Additionally, the active or passive migration feature simplified calibration.
Key Specifications
- Output signal: 4-20mA or RS485
- LCD display with backlight
- 5-digit display
- DC24V powered
- Multiple engineering unit display options
- Nonlinear correction
- Active or passive migration
- Durable housing for industrial environments
How many transmitters have you replaced only to find that the real problem was common-mode noise? For more on EMI mitigation, see [Control Engineering’s guide](https://www.controleng.com).
🔧 Need a Reliable RS485 Digital Pressure Gauge?
Contact our engineering team for a free consultation on DR3702 solutions tailored to your application.
Tags: #RS485pressuretransmitter #4-20mApressuregauge #EMIresistantpressuresensor #digitalpressuregaugewithRS485 #DR3702
