ACITEK G400-COND 4-Wire Conductivity Transformer for Pharmaceutical Purified Water System

1. Project Background

A medium-sized biopharmaceutical manufacturer in Jiangsu runs a full-process purified water system, including multi-media filtration, activated carbon filter, two-stage RO reverse osmosis, mixed ion exchange bed and finished water storage tank. Purified water is used for reagent preparation, equipment cleaning and injection auxiliary production, requiring stable conductivity ≤ 2.0 μS/cm (25°C) to meet GMP standards.

Original Monitoring Pain Points

1. Adopted old 2-wire conductivity controllers, severe measurement polarization error under low conductivity; readings fluctuated ±0.5~1.2 μS/cm, unable to judge resin failure accurately.
2. Only single 4-20mA conductivity output, no independent temperature signal; PLC could not realize automatic temperature compensation logic.
3. Single relay output only supports simple high-limit alarm, cannot interlock resin regeneration pump and RO bypass valve synchronously.
4. No intelligent sensor diagnosis function; electrode fouling or cable aging could not be pre-warned, leading to long-time unqualified water without discovery.
5. Single panel mounting mode, difficult to install beside vertical ion exchange tanks, extra bracket costs required.

Project Demand

• Stable low-conductivity detection for RO & mixed bed outlet, eliminate polarization error
• Dual independent 4-20mA outputs for conductivity + temperature synchronous transmission
• Dual floating relays for automatic linkage of regeneration and bypass protection
• Multi-installation modes: wall / pipe / panel mounting to fit all process points
• Built-in sensor monitoring & preventive maintenance reminder function
• Compatible with all analog two-electrode platinum probes (ACITEK CR-GS-10 K=10)

2. Solution Deployment

The factory fully replaced old controllers with ACITEK G400-COND 4-wire conductivity transmitters, matching CR-GS-10 platinum two-electrode sensors, complete system layout as below:

2.1 Equipment Configuration

1. Transmitter: ACITEK G400-COND, 4-wire signal acquisition, PBT reinforced industrial enclosure, 24VDC power supply;
2. Matching electrode: CR-GS-10 platinum conductivity probe, cell constant K=10, installed via G1/2 pipeline thread;
3. Signal design:
   • Channel 1 4-20mA: Conductivity value (0–20 μS/cm customized range for purified water)
   • Channel 2 4-20mA: Real-time water temperature (0–60°C)
   • Relay 1: High conductivity alarm, trigger mixed bed acid-alkali regeneration pump
   • Relay 2: Ultra-high conductivity interlock, open RO bypass valve to drain unqualified water
4. Installation layout:
   • RO front/back monitoring points: Panel mounting inside control cabinet
   • Ion exchange tank outlet: Pipe wall mounting with matching hoop accessories
   • Finished water pipeline: Wall-mounted beside flow cell
5. Calibration: On-site one-point solution calibration, support one-key factory reset for routine maintenance.

2.2 Core Technical Matching Advantages of G400-COND

1. 4-wire measurement anti-polarization technology Separate current excitation and signal collecting circuit, completely eliminate ion polarization interference in low-ion purified water, stable reading fluctuation controlled within ±0.08 μS/cm, fully meet pharmaceutical water precision requirements.
2. Dual independent 4-20mA current outputs Conductivity and temperature transmit signals separately to workshop PLC, realizing automatic 25℃ benchmark temperature compensation program, no manual parameter modification needed when water temperature changes in workshop.
3. Dual floating relay contacts for multi-linkage control Two groups of independent relays realize graded control: early warning regeneration & emergency bypass, avoid mass unqualified purified water entering production line, reduce waste loss.
4. Multi-scene flexible installation Support panel, wall and pipe three installation ways, no customized bracket required for vertical tank measuring points, cut on-site installation material and labor cost by 30%.
5. Intelligent sensor continuous monitoring & maintenance prompt Real-time judge electrode fouling, cable open/short circuit, pop up maintenance icon on high-contrast LCD screen; technicians can schedule cleaning and calibration in advance, avoid blind sampling inspection.
6. Wide adaptable cell constant range Freely set cell constant 0.005 ~ 20 cm⁻¹, compatible all existing two-electrode and four-electrode analog sensors of the factory, no need to replace original probes, save renovation investment.

3. On-Site Operation Effect After 6 Months Running

3.1 Measurement Accuracy & Stability Improvement

• Original equipment fluctuation: ±0.5~1.2 μS/cm → G400-COND fluctuation ≤ ±0.08 μS/cm
• Early warning time of resin failure advanced by 2–3 hours, avoid delayed regeneration leading to conductivity over-limit.

3.2 Automatic Control Economic Benefits

1. Purified water waste reduced by 82%: Bypass interlock function automatically cut off unqualified water, monthly loss of discarded water reduced by over 12,000 L.
2. Regeneration chemical consumption saved by 21%: Accurate conductivity threshold trigger regeneration, reduce redundant acid/alkali dosing frequency.
3. Labor maintenance cost down 65%: Intelligent diagnosis reduces daily manual sampling frequency from 4 times/day to 1 time/day, maintenance workload greatly relieved.

3.3 Environmental & Compliance Value

Continuous traceable conductivity & temperature data fully meet GMP audit data recording requirements; stable long-term operation without drift passes factory quarterly third-party water quality inspection all times.

Customer Feedback

“The ACITEK G400-COND 4-wire transmitter solved our long-standing unstable low-conductivity measurement problem. Dual signal output and dual relay linkage greatly optimize our purified water automatic control logic, the multi-installation design also simplified our on-site reconstruction work. After half a year of operation, data is stable and maintenance work is significantly reduced, which is a cost-effective upgrade solution for pharmaceutical water systems.” ——Water Treatment Supervisor, Biopharmaceutical Plant

4. Extended Application Cases of G400-COND

Case 2: Electronics Factory Ultra-Pure Water Monitoring

Matched low K=0.01 electrode, monitor EDI outlet ultra-pure water, real-time judge filter element aging, guarantee wafer cleaning water quality, support long-distance cable transmission up to 50m without signal attenuation.

Case 3: Cooling Circulating Water Blowdown Control for Machinery Factory

Set high conductivity threshold linkage blowdown valve, control water salt concentration, reduce fresh water replenishment and scale inhibitor dosage, annual water saving over 10,000 tons.

Case 4: Municipal Drinking Water Ion Exchanger Station

Wall-mounted layout for outdoor equipment room, wide temperature LCD display visible under strong light, one-year warranty reduces after-sales maintenance pressure for municipal engineering integrators.

5. Comprehensive Product Strength Summary Verified by Field Cases

1. Universal 4-wire anti-polarization measurement, cover full range 0.000 μS/cm ~ 200 mS/cm, adapt ultra-pure water to medium-concentration industrial water;
2. Dual current output + dual relay multi-linkage function, integrate measurement, display and automatic control into one unit, no extra secondary control module needed;
3. Three installation modes + dual power supply (24VDC/230VAC), fit cabinet, workshop pipeline and outdoor equipment room;
4. Intelligent sensor diagnosis + preventive maintenance prompt, lower long-term operation & maintenance cost;
5. Wide compatible cell constant and temperature sensor (Pt1000/NTC30k), support OEM/ODM customization for water equipment manufacturers;
6. Industrial PBT corrosion-resistant housing, stable continuous 24h online operation with 12-month global warranty.

6. Conclusion

ACITEK G400-COND 4-wire conductivity transmitter perfectly solves the measurement error, single control signal and single installation pain points of traditional 2-wire controllers. Verified by pharmaceutical purified water, electronic ultra-pure water, industrial circulating water and municipal water treatment projects, it provides integrated display, measurement and automatic linkage control solution for all analog conductivity sensors. For water system integrators, pharmaceutical, electronics and municipal water plants pursuing high precision and low maintenance monitoring, G400-COND is a reliable cost-performance 4-wire conductivity control host.