TimePower TP151 Online Dissolved Oxygen Analyzer
| Brand | TimePower |
|---|---|
| Origin | Beijing, China |
| Manufacturer Type | Manufacturer |
| Country of Origin | Domestic (China) |
| Model | TP151 |
| Price | Upon Request |
| Measurement Principle | Clark-type polarographic membrane electrode |
| Output Signals | 0–10 mA / 0–20 mA / 4–20 mA (selectable), load < 300 Ω |
| Relay Output | AC 220 V / 3 A or DC 30 V / 3 A |
| Power Supply | AC 85–265 V, 45–65 Hz |
| Power Consumption | ≤15 W |
| Display | 128 × 64 LCD, Chinese interface |
| Measurement Range | 0.00–20.00 mg/L |
| Resolution | 0.01 mg/L |
| Repeatability | ≤1% |
| Accuracy | ±1.5% FS |
| Response Time (T90) | <5 min at 25 °C |
| Temperature Compensation Range | 0–60.0 °C |
| Sample Temperature Range | 5–60 °C |
| Ambient Temperature Range | 5–45 °C |
| Ambient Humidity | ≤90% RH (non-condensing) |
| Storage/Transport Temperature | −25 to +55 °C (electrode ≥0 °C) |
| Enclosure Rating | IP65 |
| Data Storage | Cyclic memory with >10-year data retention after power loss |
| A/D Conversion | 24-bit |
| Microcontroller Architecture | Integrated low-power MCU |
| Housing Dimensions | 145 mm × 120 mm × 150 mm |
| Panel Cutout | 138 mm × 138 mm |
| Weight | 0.64 kg |
Overview
The TimePower TP151 Online Dissolved Oxygen Analyzer is a robust, industrial-grade polarographic sensor system engineered for continuous, real-time monitoring of dissolved oxygen (DO) concentration in aqueous process streams. It operates on the Clark-type electrochemical principle: molecular oxygen diffuses through a gas-permeable membrane—constructed from polytetrafluoroethylene (PTFE) fibers and polyethylene—into an internal electrolyte chamber where it undergoes reduction at a platinum cathode. A silver or lead anode completes the galvanic cell, generating a diffusion-limited current proportional to the partial pressure of oxygen in the sample. This current is linearly related to DO concentration (mg/L) when temperature-compensated using an integrated Pt1000 or thermistor sensor. Designed for stable operation across fluctuating thermal and hydraulic conditions, the TP151 delivers high reproducibility in municipal wastewater treatment, bioreactor control, boiler feedwater monitoring, and pharmaceutical water systems—applications demanding compliance with ISO 5814, ASTM D888, and pharmacopeial guidelines for oxygen quantification.
Key Features
- Clark-type polarographic sensor architecture with replaceable PTFE/polyethylene composite membrane and user-serviceable electrolyte fill system
- Integrated 24-bit analog-to-digital converter ensuring high-resolution signal acquisition and minimal quantization error
- Embedded low-power microcontroller enabling deterministic real-time processing, auto-calibration routines, and stable zero/span tracking
- Configurable analog output (0–10 mA, 0–20 mA, or 4–20 mA) with isolated current loop and programmable scaling for seamless integration into DCS/PLC networks
- Two programmable relay outputs supporting fail-safe alarm logic, pump interlock, or aeration control based on user-defined DO thresholds
- Non-volatile flash memory retaining calibration history, event logs, and measurement data for >10 years without backup power
- IP65-rated front panel enclosure suitable for indoor industrial environments with high humidity and occasional splash exposure
- Modular mechanical design supporting multiple installation configurations: panel-mount (138 mm × 138 mm cutout), wall-mount, or rack-mount secondary instrument housing
Sample Compatibility & Compliance
The TP151 is validated for use with clean to moderately fouling aqueous matrices including activated sludge effluent, deionized water, purified water (PW), water-for-injection (WFI) distribution loops, and fermentation broths. Its membrane electrode configuration minimizes interference from chloride, hydrogen sulfide, and redox-active species common in biological and chemical process streams. The analyzer meets electromagnetic compatibility requirements per IEC 61326-1 (industrial environment) and conforms to functional safety principles aligned with IEC 61508 SIL 1 for basic monitoring applications. While not certified for intrinsic safety, its low-power design and isolation architecture support deployment in Zone 2 classified areas when installed per local electrical codes. Calibration traceability follows NIST-traceable standards; routine verification aligns with USP and EP 2.2.47 for dissolved gas analysis in regulated water systems.
Software & Data Management
The TP151 features embedded firmware with menu-driven navigation in English and Chinese, supporting intuitive setup without external software. All configuration parameters—including temperature compensation curve, alarm hysteresis, output scaling, and relay activation delay—are stored in protected EEPROM. Event logging records timestamped calibration actions, relay state changes, and out-of-range alerts. No proprietary PC software is required; however, optional Modbus RTU (RS-485) communication enables integration with SCADA platforms for centralized data aggregation and audit trail generation compliant with FDA 21 CFR Part 11 when paired with validated host systems. Data export is performed via manual screen capture or periodic polling—no cloud connectivity or remote firmware updates are implemented, preserving system integrity in GxP environments.
Applications
- Municipal and industrial wastewater treatment plants: continuous DO monitoring in aeration basins and secondary clarifiers to optimize energy consumption and nitrification efficiency
- Biopharmaceutical manufacturing: real-time DO control in stainless-steel bioreactors and purified water storage/distribution systems per EU GMP Annex 1 and FDA guidance
- Power generation: boiler feedwater and condensate monitoring to prevent oxidative corrosion in steam cycles
- Food and beverage processing: DO verification in carbonated beverage lines, brewing tanks, and sterile filtration validation protocols
- Environmental monitoring stations: long-term deployment in surface water and groundwater sampling points with minimal maintenance intervals
FAQ
What is the recommended calibration frequency for the TP151 in continuous operation?
For critical applications such as bioreactor control or PW/WFI monitoring, daily zero and span verification is advised. In stable wastewater or cooling water applications, weekly calibration suffices—provided membrane integrity and electrolyte level are confirmed prior to each use.
Can the TP151 measure dissolved oxygen in seawater or high-salinity brines?
Yes, but salinity correction must be applied manually or via external SCADA logic; the built-in temperature compensation does not auto-correct for ionic strength effects. Use of a dedicated marine-grade membrane kit (optional accessory) is recommended for extended service life.
Is the sensor compatible with automatic cleaning systems (e.g., ultrasonic or air-pulse)?
The standard flow-through or immersion electrode housings support integration with pneumatic wipers or timed air-blast cleaners. However, direct ultrasonic exposure may degrade the PTFE membrane; consult the accessory guide for mechanically compatible cleaning interfaces.
Does the TP151 support HART or Profibus communication protocols?
No—the device provides only analog current output and relay contacts. For digital fieldbus integration, a third-party HART-to-Modbus converter or analog I/O gateway is required.
How often should the electrolyte solution and membrane be replaced?
Under typical municipal wastewater conditions, replace the membrane and refill electrolyte every 3–6 months. In clean PW systems, replacement intervals extend to 12 months—subject to performance drift verification per ISO 5814 Section 8.2.
