Accurate measurement of dissolved oxygen is critical across numerous industries, from wastewater treatment and environmental monitoring to food and beverage production and pharmaceutical manufacturing. The Hach 51811-03 Portable LDO Probe represents the gold standard in portable dissolved oxygen sensing technology, offering exceptional accuracy, rapid response times, and the rugged reliability that Hach Company has built its reputation on for over 80 years.

This innovative LDO (Luminescent Dissolved Oxygen) probe from Hach Company Chicago utilizes advanced luminescence-based sensing technology to eliminate many of the maintenance challenges associated with traditional membrane-based dissolved oxygen sensors. Unlike conventional DO probes that require regular membrane replacement and electrolyte refilling, the LDO probe uses a luminescent sensor cap that provides stable, drift-free measurements with minimal maintenance requirements. This makes it an ideal choice for field applications, remote monitoring locations, and any environment where sensor reliability and reduced maintenance are priorities.

At Pvt. Ltd., we are committed to providing our customers with the highest quality analytical instrumentation and water quality monitoring equipment. The Hach 51811-03 Portable LDO Probe with 1-meter cable is offered in new condition, backed by our standard 30-day warranty and free worldwide shipping. Whether you are monitoring dissolved oxygen levels in an industrial process stream, conducting environmental water quality assessments, or ensuring compliance with regulatory discharge limits, this Hach LDO probe delivers the precision and dependability your application requires.

Key Features & Specifications of the Hach 51811-03 LDO Probe

The Hach 51811-03 Portable LDO Probe incorporates cutting-edge sensor technology and thoughtful engineering to deliver outstanding performance in dissolved oxygen measurement. Here are the key features that distinguish this probe from conventional DO sensors:

• Luminescent Sensing Technology: The LDO probe uses advanced luminescence-based measurement principles that eliminate the need for membranes, electrolytes, and frequent calibration associated with traditional galvanic or polarographic DO sensors.
• Portable Design: Engineered for field use with a lightweight construction weighing only 420 grams, making it easy to transport and deploy at multiple sampling locations.
• 1-Meter Cable Length: The probe is equipped with a 1-meter cable that provides adequate reach for most portable measurement applications while maintaining signal integrity.
• Reference Standard: Based on the proven 51811-01 design platform, ensuring compatibility with established Hach instrumentation and measurement protocols.
• Part Number: 51811-03, a 3-meter LDO probe variant from Hach's comprehensive dissolved oxygen sensor portfolio.
• Trusted Manufacturer: Manufactured by Hach Company, a global leader in water quality analysis and analytical instrumentation based in Chicago, USA.
• Minimal Maintenance: The luminescent sensor cap design dramatically reduces maintenance requirements compared to traditional DO probes, saving time and operational costs.

Technical Specifications

Specification	Details
Manufacturer	Hach Company, Chicago
Part Number	51811-03
Product Type	Portable LDO Probe
Cable Length	1 Meter
Reference	51811-01 (Design Base)
Measurement Technology	Luminescent Dissolved Oxygen (LDO)
Weight	420 Grams

Applications & Use Cases

The Hach 51811-03 Portable LDO Probe is a versatile analytical instrument suitable for a broad spectrum of dissolved oxygen measurement applications across multiple industries:

Wastewater Treatment

Municipal and industrial wastewater treatment facilities rely on accurate dissolved oxygen measurements to optimize biological treatment processes. The LDO probe provides the precision needed for aeration basin control, ensuring efficient biological oxygen demand (BOD) removal while minimizing energy consumption.

Environmental Monitoring

Environmental scientists and regulatory compliance officers use portable LDO probes to assess water quality in rivers, lakes, estuaries, and coastal waters. Dissolved oxygen is a critical indicator of aquatic ecosystem health, and the Hach LDO probe enables rapid, accurate field measurements without the logistical challenges of traditional DO analysis.

Food and Beverage Production

Breweries, wineries, and food processing facilities monitor dissolved oxygen at various stages of production to ensure product quality and prevent oxidation. The portable design of the 51811-03 probe allows quality control personnel to take measurements at multiple points throughout the production facility.

Pharmaceutical and Biotechnology

Pharmaceutical manufacturing and bioprocessing applications require precise dissolved oxygen control to maintain optimal cell culture conditions and ensure product consistency. The LDO probe's low-maintenance design and stable measurements make it well-suited for GMP-regulated environments.

Aquaculture

Fish farms and aquaculture operations depend on continuous dissolved oxygen monitoring to maintain healthy growing conditions. The Hach LDO probe provides the accuracy and reliability needed to prevent oxygen-related stress or mortality in intensive aquaculture systems.

Industrial Process Water

Power plants, chemical processing facilities, and pulp and paper mills use the LDO probe to monitor dissolved oxygen in process water, cooling water, and boiler feedwater systems. Controlling DO levels helps prevent corrosion, optimize chemical treatment programs, and ensure compliance with discharge regulations.

Why Choose the Hach 51811-03 Portable LDO Probe

When selecting a dissolved oxygen sensor for your application, the Hach 51811-03 LDO Probe offers several distinct advantages that set it apart from competing technologies:

Luminescent Technology Eliminates Traditional Maintenance

Traditional dissolved oxygen sensors require periodic replacement of membranes and electrolyte solutions, as well as frequent calibration to maintain accuracy. The LDO probe's luminescent sensor cap eliminates these maintenance tasks entirely, reducing operational costs and minimizing sensor downtime. Simply replace the sensor cap when needed, and the probe returns to accurate operation without complex calibration procedures.

Exceptional Long-Term Stability

The luminescent sensing element exhibits minimal drift over time, providing consistently accurate measurements with extended calibration intervals. This stability is particularly valuable in remote monitoring applications and automated process control systems where frequent calibration is impractical or costly.

Rapid Response Time

The LDO probe responds quickly to changes in dissolved oxygen concentration, enabling real-time process control and rapid detection of process upsets. Fast response times are essential in applications such as aeration control, where delayed measurements can result in energy waste or inadequate treatment.

Trusted Brand Heritage

Hach Company has been a pioneer in water quality analysis for over eight decades, earning the trust of water professionals in more than 100 countries worldwide. The company's commitment to innovation, quality, and customer support ensures that Hach products deliver reliable performance throughout their operational lifetime.

Compatibility & Integration

The Hach 51811-03 Portable LDO Probe is designed for compatibility with Hach's family of portable and laboratory dissolved oxygen meters. Integration considerations include:

• Hach Portable Meters: The probe connects seamlessly to Hach's range of portable DO meters, providing plug-and-play convenience for field measurement applications.
• Signal Output: The LDO probe generates a digital signal compatible with Hach instrumentation, ensuring accurate data transmission over the 1-meter cable length.
• Sensor Cap Compatibility: Uses standard Hach LDO sensor caps that are readily available for replacement when needed, ensuring continuous measurement availability.
• Data Management: When paired with compatible Hach meters, measurement data can be stored, reviewed, and transferred to PC-based data management systems for reporting and compliance documentation.

Maintenance & Support

One of the primary advantages of the LDO probe technology is its significantly reduced maintenance burden compared to traditional dissolved oxygen sensors. Routine maintenance is limited to periodic cleaning of the sensor body to remove biofilm or deposit buildup, and replacement of the luminescent sensor cap when its service life has been reached.

At , we stand behind every product we sell. This Hach 51811-03 Portable LDO Probe comes with our standard 30-day warranty and free worldwide shipping. Our knowledgeable customer support team is available to assist with product inquiries, technical questions, and after-sales service. We understand that your analytical instrumentation is critical to your operations, and we are committed to ensuring your complete satisfaction with every purchase.

Frequently Asked Questions

Q1: What does LDO stand for in the Hach 51811-03 probe?

LDO stands for Luminescent Dissolved Oxygen. This measurement technology uses a luminescent sensor cap that emits light in response to blue LED excitation. The intensity and duration of the luminescence are inversely proportional to the dissolved oxygen concentration in the sample, enabling precise oxygen measurement without traditional membranes or electrolytes.

Q2: What is the cable length of this Hach LDO probe?

The Hach 51811-03 Portable LDO Probe is equipped with a 1-meter (approximately 3-foot) cable, providing sufficient length for portable measurement applications while maintaining signal integrity between the probe and the connected meter.

Q3: Is this a new or used Hach LDO probe?

This Hach 51811-03 Portable LDO Probe is offered in new condition, sourced directly from Hach Company's supply chain. It comes with 's 30-day warranty and free worldwide shipping.

Q4: What industries commonly use the Hach LDO probe?

The Hach LDO probe is widely used across wastewater treatment, environmental monitoring, food and beverage production, pharmaceutical manufacturing, aquaculture, power generation, chemical processing, and pulp and paper industries wherever accurate dissolved oxygen measurement is required.

Q5: How does luminescent DO technology compare to traditional membrane-based sensors?

Luminescent DO technology eliminates the need for membrane replacement, electrolyte refilling, and frequent calibration associated with traditional galvanic or polarographic sensors. LDO probes offer superior long-term stability, reduced maintenance requirements, and faster response times, resulting in lower total cost of ownership.

Q6: What is the weight of this portable LDO probe?

The Hach 51811-03 Portable LDO Probe weighs approximately 420 grams, making it lightweight and easy to carry for field measurements and portable water quality monitoring applications.

Q7: What warranty does provide for this product?

offers a standard 30-day warranty on this Hach 51811-03 LDO Probe along with free worldwide shipping. Our customer support team is available to address any questions or concerns regarding your purchase.

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