Do Meter

ACITEK G300 Online DO Transmitter + DO6800 High-temperature Dissolved Oxygen Electrode

1. Project Background
A fine chemical enterprise produces 50,000 tons of acrylate annually. Its reaction kettles operate at 80–120℃ and 0.6–1.0 MPa. Dissolved Oxygen (DO) must be strictly controlled within 0.5–1.5 mg/L. Excess DO causes side reactions and reduces product purity, while insufficient DO leads to incomplete chemical reaction and lower output.

The traditional polarographic electrodes suffered severe signal drift above 60℃, with membranes aging every 2–3 weeks. Frequent shutdown for calibration and replacement brought high maintenance costs and disrupted continuous production. The site adopted ACITEK G300 DO Transmitter + DO6800 High-temperature DO Electrode to solve the problems.



2. Product Specifications
ACITEK G300 Online DO Transmitter

Measuring range: 0.00–40.00 ppm, Accuracy: ±0.01 ppm
Working temperature: -10.0–130.0℃, automatic temperature compensation
Output: 4-20mA & Modbus RTU, compatible with DCS system
Protection class: IP65, explosion-proof design







ACITEK DO6800 High-temperature DO Electrode

Temperature resistance: 0–130℃, supports 130℃ SIP sterilization
Housing: 316L stainless steel, acid & alkali resistant
High-temperature resistant membrane, anti-aging and anti-fouling
Response time: t90 ≤ 60 s




3. Installation & Commissioning

Mounted on DN50 side port of reaction kettle, immersed 20–30 cm below liquid level, away from agitator and inlet to avoid bubble interference.
Shielded cabling to prevent electromagnetic interference.
Two-point calibration with oxygen-free water and air-saturated water. Stable performance lasts over 6 months after one calibration.
Linked with DCS: Automatic nitrogen purge when DO below set value; cut off nitrogen supply when DO exceeds limit.

4. Application Results (6-month operation)

Stable measurement: No signal drift at 120℃, DO fluctuation controlled within ±0.1 mg/L.
Low maintenance: Membrane service life extended from 2–3 weeks to 8–10 months. Calibration cycle reaches 6 months, maintenance workload reduced by over 70%.
Quality improvement: Acrylate purity rose from 99.2% to 99.7%, high-grade product rate increased by 12%.
Higher efficiency: Gas consumption cut by 18%. Shutdowns caused by DO faults were eliminated, with annual output increased by 2000 tons.
Durable performance: Continuous trouble-free operation for 180 days, no corrosion orscaling on electrode.

5. Customer Feedback
"This high-temperature DO monitoring solution perfectly solves our pain points of unstable reading and frequent maintenance. The G300 transmitter delivers reliable data and smooth communication. The DO6800 electrode works well under high temperature. It greatly guarantees our continuous production and product quality." — Manager Wang, Equipment Department

6. Applicable Scenarios

Chemical industry: High-temperature reaction kettles, polymerization & oxidation processes, high-temperature wastewater
Pharmaceutical industry: Fermenters with 121℃ SIP sterilization
Power industry: Boiler feed water and condensed water trace oxygen monitoring
Environmental protection: High-temperature industrial wastewater & leachate treatment

1. Product Application Overview
ACITEK G100-DO is a miniature DIN rail-mounted dissolved oxygen (DO) transmitter specially designed for industrial process water quality monitoring. With an ultra-narrow 12.5 mm modular housing, 4–20 mA active analog output, RS485 communication, 24 VDC power supply and integrated temperature measurement function, it perfectly solves the installation limitation of narrow control cabinets, compact fermenters and small-scale process monitoring stations. Matched with 12 mm diameter 316L stainless steel DO sensor (IP65 protection), it delivers fast response within 1 minute and stable long-term measurement, widely deployed in chemical, pharmaceutical, biotechnology, food & beverage, energy industries, industrial wastewater treatment and laboratory process analysis. The complete package includes DIN rail transmitter, stainless steel DO sensor, mounting fittings, signal cable, flow cell and operation manual, supporting OEM & ODM customized service for diversified on-site working conditionsacitekinst....

2. Industry-Specific Application Scenarios
2.1 Biotechnology & Pharmaceutical Fermentation
Biopharmaceutical and microbial fermentation processes require precise real-time dissolved oxygen control to guarantee strain reproduction, metabolite yield and drug purity.


Core application: Small & medium-sized bioreactors, seed culture tanks, cell culture lines.
Application advantages:

Ultra-thin 12.5 mm body allows centralized installation in dense PLC control cabinets with multi-channel parameter transmitters (pH, conductivity, DO) without cabinet space shortage.
Built-in manual calibration keys (K3/K4) support on-site one-point/two-point calibration without extra handheld calibrators; calibration cycle is recommended once every 3 months to sustain measurement accuracy.
Stainless steel 1.4435 sensor probe adapts to repeated SIP/CIP high-temperature sterilization sanitary working conditions, avoiding corrosion from culture medium and organic solvents.
4–20 mA signal connects to DCS/PLC to realize automatic linkage of stirring speed and aeration flow, stabilizing DO concentration in fermentation broth and improving production batch consistency.


Typical case: Antibiotic, amino acid, vaccine cell culture production lines.

2.2 Food & Beverage Production
Dissolved oxygen directly determines product flavor, shelf life and oxidation stability in food processing.


Core application: Beer/wine fermentation, pure water production, beverage filling pretreatment, dairy processing.
Working value:

Monitor low-level residual oxygen in finished water and beverage pipelines to suppress fat oxidation, color fading and flavor deterioration.
Fermentation tank online monitoring: control oxygen supply in yeast growth stage to avoid excessive DO causing off-flavor in finished wine.
Compact DIN rail design fits small beverage factory central control cabinets, realizing multi-point DO monitoring for multiple production lines with low overall investment cost.


Matching hardware: 12 mm stainless steel sanitary DO sensor with silicone sealing, compatible with food-grade fluid pipelines.

2.3 Chemical Industry Process Monitoring
Chemical synthesis, polymerization and fine chemical reactions are sensitive to dissolved oxygen to prevent invalid oxidation side reactions.


Application points: Chemical reaction kettles, solvent recovery systems, intermediate water circulation pipelines, fine chemical pilot test lines.
Product highlights for chemical sites:

4-wire system with 14–24 VDC wide voltage power supply, stable signal transmission under factory electromagnetic interference.
RS485 Modbus communication supports distributed networking, enabling centralized remote data collection of dozens of monitoring points.
Low-cost modular measurement station solution, ideal for small-batch pilot chemical workshops with limited cabinet space.



2.4 Energy & Power Industry Water Treatment
High dissolved oxygen in boiler feed water, cooling circulating water and thermal power sampling water will cause pipeline and equipment corrosion, shortening service life.


Core scenario: Thermal power plant condensate sampling rack, boiler deaerator outlet monitoring, cooling water circulation system.
On-site advantages:

Slim DIN rail transmitter can be densely arranged on sampling rack small-sized control boxes.
Synchronous measurement of dissolved oxygen and medium temperature, providing dual-parameter data for water chemical supervision.
4–20 mA analog signal uploads DO data to power plant monitoring system to trigger deaeration equipment linkage control.



2.5 Industrial Wastewater & Environmental Water Treatment
Aerobic and anaerobic biochemical tanks rely on precise DO adjustment to optimize activated sludge treatment efficiency and reduce aeration energy consumption.


Applications: Factory sewage treatment stations, small municipal wastewater aerobic tanks, discharge water quality monitoring wells.
Field performance:

IP65 stainless steel sensor probe resists sludge adhesion and weak corrosive wastewater medium.
Fast 1-minute response time timely reflects DO fluctuation in biochemical tanks to adjust fan operation frequency and cut power consumption.
Low maintenance cost, suitable for scattered small sewage treatment stations with limited operation manpower.



2.6 Laboratory & Pilot Test Equipment
Universities, R&D laboratories and pilot workshops have compact test equipment with limited installation space.


Usage scene: Laboratory bench bioreactors, small water quality test circulation devices, material oxidation test systems.
Laboratory advantages: Miniature transmitter saves laboratory control box space; simple manual calibration operation meets frequent experimental parameter calibration demands; one-year warranty and customizable OEM labels support laboratory self-developed test equipment matching.

3. Installation & System Application Modes
3.1 DIN Rail Central Cabinet Installation
The G100-DO transmitter adopts standard 35 mm DIN rail mounting, dozens of units can be side-by-side installed together with pH, conductivity transmitters inside narrow control cabinets, realizing multi-parameter centralized monitoring of the whole production line, which is the most mainstream application mode for medium and small factories.

3.2 Independent Small-Scale Monitoring Station
Matched with flow chamber, mounting bracket and cable, it forms a complete compact DO measuring station for single reactor, single pipeline or single wastewater tank independent monitoring, without large integrated analysis cabinet, greatly reducing equipment procurement and cabinet transformation cost.

3.3 PLC/DCS Automatic Control System Integration

Analog output: 4–20 mA active current signal accesses PLC analog module to realize closed-loop automatic control of aeration, stirring, deaeration equipment.
Digital communication: RS485 Modbus-RTU connects to industrial gateway, uploading DO & temperature data to upper computer, SCADA or cloud platform for remote real-time viewing and historical data recording.

4. Application Advantages Over Traditional Large DO Transmitters

Space-saving layout: Only 12.5 mm width, solving the installation bottleneck of narrow cabinets and compact equipment that large display transmitters cannot fit.
Cost-effective construction: Low unit price plus modular assembly reduces the total investment of multi-point monitoring stations, especially suitable for small factories and pilot projects.
Wide universal compatibility: One set of equipment covers biotech, food, chemical, energy and environmental protection industries; stainless steel sensor adapts to sanitary, corrosive and aqueous working conditions.
Easy on-site maintenance: Independent K3/K4 calibration buttons support field calibration without removing the transmitter from the cabinet; recommended quarterly calibration ensures long-term stable measurement.
Dual signal output: Simultaneous 4–20 mA analog and RS485 digital communication, compatible with both traditional PLC control and modern industrial internet remote monitoring systems.

5. Application Matching Notes

For sanitary fermentation and food production, select 1.4435 stainless steel sanitary DO sensor; for chemical wastewater, 316L stainless steel probe is recommended.
The transmitter body protection grade is IP20, so it must be installed inside closed control cabinets; the matched DO sensor reaches IP65 and can be directly inserted into pipelines or tanks.
Power supply range: 14–24 VDC 4-wire connection, avoid long-distance thin wire power supply to prevent voltage drop affecting measurement stability.
OEM/ODM customization is available for special industrial application requirements, including logo printing, cable length adjustment and flow chamber modification.