Industrial 5-in-1 Water Quality PHEC Sensor Transmitter with Display Stainless Steel PHEC0.1

Specifications

• Operating Voltage: 12V–24V DC
  
• Communication Interface: RS485 (Modbus) + 2× independent 4-20mA analog current loop outputs
  
• Display: Integrated LCD with backlight
  
• Measured Parameters (5-in-1): pH, ORP, EC, TDS, Salinity
  
• pH: Resolution 0.01, Range 0–14, Accuracy ±0.05
  
• EC: Resolution 1 µS/cm, Accuracy ±2% (stainless steel probe — more resistant to corrosion and biofouling than standard plastic probes, suited to higher-salinity and industrial fluids)
  
• TDS: Resolution 1 ppm, Range 0–1000 ppm, Accuracy ±2%
  
• Temperature: Resolution 0.1°C, Range 0–60°C, Accuracy ±0.5°C
  
• Salinity: Resolution 0.01%, Range 0–25%, Accuracy ±0.1%
  
• Sensor Inputs: BNC connector (pH/ORP combination electrode), 4-terminal connector for EC probe (Ta/Tb temp. compensation + C+/C- conductivity)
  
• Included Probes: 1× pH/ORP combination electrode (BNC, long cable), 1× stainless steel EC probe (PG7 waterproof cable gland)
  
• Mounting: DIN-rail style transmitter housing

Minimum Hardware

• 12V or 24V DC regulated power supply: same requirement as the Standard variant; the transmitter electronics are identical
  
• RS485-to-USB converter :needed if reading Modbus data on a PC or single-board computer
  
• PLC or microcontroller with RS485/Modbus support :  required to capture and log the transmitter's output
  
• Mounting bracket or clamp for the stainless steel probe : recommended for fixed installation in flowing or turbulent water where the probe needs to stay positioned correctly

Safety Warnings:

• Voltage Warning: 12–24V DC : NOT 5V or 3.3V logic level, do not connect directly to a microcontroller's logic pins
  
• Polarity Warning: Reversing VCC and GND can damage the transmitter's internal circuitry
  
• Galvanic Note: When using a stainless steel probe in metal tanks or near other metal fixtures, ensure proper grounding to avoid galvanic interference affecting EC readings
  
• Probe Handling: While the stainless steel body is far more rugged than plastic, avoid dragging the probe across abrasive surfaces  this can scratch the electrode surface and affect calibration accuracy

Accessories Included in the Box:

• 1× PHEC0.1 Transmitter Unit (with LCD display)
• 1× pH/ORP Combination Electrode (BNC connector, long cable)
• 1× Stainless Steel EC Probe (PG7 waterproof cable gland, long cable)

Frequently Asked Questions

• What's the difference between the Standard PHEC 1.0 and the Stainless Steel PHEC0.1?"
  The Standard PHEC 1.0 uses a plastic-bodied EC probe, ideal for clean water like aquaculture, hydroponics, and drinking water testing. The PHEC0.1 uses a stainless steel EC probe instead, built to resist corrosion and UV degradation for industrial wastewater, brine, or outdoor deployments where a plastic probe would wear out faster.
• Is the PHEC0.1 compatible with a standard PLC?
  Yes, it outputs both RS485 Modbus and 4-20mA current loop signals, the two most common industrial input types supported by nearly all PLCs.
  
• Can I connect the PHEC0.1 to an Arduino or Raspberry Pi?
  Yes, but you'll need an RS485 module such as the MAX485 for Arduino, or a USB-to-RS485 converter for Raspberry Pi.
  
• Does the PHEC0.1 work with SCADA software?
  Yes, since it uses standard Modbus RTU protocol via RS485, it integrates with most SCADA systems supporting Modbus devices.
  
• Is the stainless steel probe compatible with the Standard PHEC 1.0 transmitter?
  No — treat these as matched pairs; the probe and transmitter calibration are tied together as sold, so don't mix probes between the Standard and Stainless Steel variants.
• What voltage does the PHEC0.1 require?
  It requires a 12V to 24V DC power supply, same as the Standard variant — the transmitter electronics are identical.
  
• Can I power the PHEC0.1 from a 5V source?
  No, 5V is below the minimum rated input of 12V DC and will prevent proper operation.
  
• What happens if I reverse the VCC and GND wiring?
  Reversed polarity can damage the transmitter's internal circuitry — always verify polarity with a multimeter before first power-on.
• How do I wire the PHEC0.1 for RS485 communication?
  Connect the A and B terminals to your RS485 converter or PLC's corresponding A/B terminals using a twisted-pair cable.
  
• What do the mA1 and mA2 terminals do?
  These are two independent 4-20mA current loop outputs, typically mapped to two of the measured parameters for direct analog PLC integration.
  
• Does the stainless steel probe need any special grounding?
  Yes — if installing near metal tanks or fixtures, ensure proper grounding to prevent galvanic interference from affecting EC readings.
• Why is my PHEC0.1 showing no reading on the display?
  Confirm your DC supply is within the 12-24V range and that VCC/GND polarity is correct at the terminal block.
  
• Why are my EC readings inconsistent with the stainless steel probe?
  This is often caused by biofouling or mineral buildup on the metal electrode surface — clean the probe with a soft brush and recalibrate using EC standard solution.
  
• Why is my RS485 communication not working?
  Check that A and B wires aren't swapped, confirm your converter's baud rate matches the transmitter's default, and verify a common ground exists.
  
• Does the stainless steel probe corrode over time in harsh water?
  It's built to resist corrosion far better than plastic probes, but periodic inspection is still recommended in highly acidic or chemically aggressive environments.