Solution Ground pH Controller for Power Plant Water

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Model No.	APX2-G4
Brand Name	daruifuno
Support customization	Oem
place of origin	China

Description

Continuously and accurately measuring and controlling the pH value of the water vapor system in power plants is one of the main means to control metal corrosion in the water vapor system. The difficulty of pH monitoring in power plants lies in the high-purity water samples such as feed water, condensate water and steam. There are many special interference problems in accurately measuring the pH value, resulting in large errors in the actual measurement values of many power plants, causing corrosion of the water vapor system. The water purity of the water vapor system of thermal power generating units is very high. It is generally not allowed to add corrosion inhibitors. The pH value of the water is mainly adjusted by adding ammonia, and a small amount of deoxidizer or oxygen is added to achieve the purpose of preventing metal corrosion in the water vapor system. In order to prevent corrosion of steel and copper in water and steam systems, it is generally required to control the pH value of water within a strict range, which requires the use of pH sensors and pH controllers. The APX2-G4 model online pH ORP controller developed and produced by Daruifuno is specially designed for power plant pure water with ASP500 solution ground electrode. The controller has two relays that can set high and low alarms, and automatically adjusts the pH value according to the pH value measured by the pH electrode. The medicine pump controls the pH value within a certain range.

Core Technologies

Delfino's?APX2-G4?is engineered specifically for power plant applications, featuring:

Solution Ground Electrode (ASP500):?Enables accurate pH measurement in < 5 μS/cm water by eliminating reference potential errors.
Dual-Relay Control:?High/low pH alarms with PID-linked dosing pump integration for ±0.1 pH precision.
Temperature Compensation:?Real-time NTC sensor (0-130°C range) with non-linear correction algorithms.
Anti-Interference Design:?316L stainless steel flow cell, 1Ω grounding resistance, and 80 dB electromagnetic shielding.

Key Performance Advantages

Accuracy:?±0.02 pH (NIST-calibrated) vs. ±0.1 pH for conventional systems.
Response Speed:?T90 < 15 seconds (pH 7→10) vs. 60-90 seconds for standard electrodes.
Maintenance Costs:?60% reduction through 2-year electrode lifespan and predictive calibration.
Compliance:?Meets GB/T 12145-2016 standards for power plant water quality.

Specification

Product Name	PH ORP?Controller
Product Model	APX2-G4
pH Sensor Input	Glass pH sensor
ORP Sensor Input	ORP sensor (Platinum/Gold sensor)
ORP Range	-2000~+2000mV
Operating Temperature	0~60℃ RH<95%
Accuracy	PH: ±0.02pH /ORP: ±2mV
Relay Output	Two SPST relays max. load 3A/250VAC
Analog Output	Two 0/4~20mA current outputs
Communication Method	RS485 interface
Solution Ground	support to connect with the SG sensor
Protection Grade	IP66
Material	Enhanced ABS
Dimension	144144120cm

PH ORP Controller Five Calibration Points

The boiler water and boiler feed water in the power plant are ultrapure water with very low conductivity. Years of field application have proven that the factors that affect the measurement accuracy of the online pH analyzer are: electrostatic charge, liquid junction potential, temperature, glass electrode quality, electrode Response time, contamination of the electrode surface, electrode usage time, grounding conditions, external interference and other factors. Therefore, ordinary pH analyzer measurements will have measurement deviations.

How to reduce the interference of pure water on pH value measurement? There are several targeted measures:
1. The pH flow cell and connecting tubes should be made of stainless steel, preferably 316 stainless steel, or electrolytically polished 304 stainless steel, and the entire system should be well grounded to eliminate the influence of static electricity. At the same time, the entire measurement system is required to have good sealing and shielding properties to reduce electromagnetic interference and prevent air from leaking into the water, causing measurement errors.
2. For pH controllers, it is necessary to have a temperature compensation function to eliminate errors caused by temperature changes. Additionally, there is a separate solution ground connection to eliminate the effects of ground loops. Provides a variety of calibration functions for higher accuracy measurements.
3. Influence of flow rate and pressure: The flow rate of water sample flowing through the flow cell should be controlled within a certain range, because the potential output of low conductivity water pH measurement will change with the change of water sample flow rate.

online pH controller
The ASP500 electrode has a solution ground and can measure water quality with conductivity below 5uS/cm. If you are interested in this sensor, you can find its specifications in the pH sensor category.

For more than ten years, Daruifuno has been focusing on the research and development and production of water quality analysis instruments. Our extensive product line includes not only pH ORP Controller & pH ORP Transmitter, but also analyzers/meters, controllers and sensors/probes/electrodes for key Water Quality Parameters such as pH, ORP, conductivity, Turbidity, COD, dissolved oxygen, ammonium and chlorine. If you are interested in our Solution Ground pH Controllers for Power Plant Water or any other products, please feel free to contact us.