Hach 146900 Dissolved Oxygen Test Kit, Model OX-2P

1. Introduction

The Hach 146900 Dissolved Oxygen Test Kit, Model OX-2P, is designed for the accurate determination of dissolved oxygen concentration in water samples. This kit utilizes a simple and economical drop count titration method, making it suitable for field and laboratory use. It provides all necessary reagents and apparatus for approximately 100 tests, conveniently packaged in a durable plastic carrying case.

2. Kit Components and Setup

Before beginning any tests, ensure all components are present and in good condition. Familiarize yourself with each item in the kit.

Figure 2.1: Overview of the Hach 146900 Dissolved Oxygen Test Kit components. This image displays the complete kit contents, including the carrying case, various reagent bottles, powder packets, a test tube, and other necessary apparatus for conducting dissolved oxygen measurements.

Figure 2.2: The Hach 146900 Dissolved Oxygen Test Kit with the lid open, revealing the organized storage of reagents and testing apparatus. This view highlights the specific reagent bottles and packets, such as PERMACHEM reagents, stored within the kit's carrying case.

The kit typically includes:

• Plastic Carrying Case
• Reagent Bottles (e.g., Manganous Sulfate Solution, Alkaline Iodide-Azide Reagent, Sulfuric Acid)
• PERMACHEM Reagent Powder Pillows
• Titration Apparatus (e.g., Titration Tube, Measuring Tube)
• Dropper Bottle for Titrant
• Sample Bottles

Ensure all bottles are securely capped and powder pillows are sealed. Store the kit in a cool, dry place away from direct sunlight.

3. Operating Instructions (Drop Count Titration Method)

This section outlines the general procedure for determining dissolved oxygen using the drop count titration method. Always refer to the specific instructions provided with your reagent lot for precise details, as procedures may vary slightly.

3.1. Sample Collection

1. Collect a water sample carefully to avoid aeration. Fill the sample bottle completely, allowing some overflow, then cap it without trapping air bubbles.
2. Perform the test immediately after sample collection for most accurate results, especially for unstable samples.

3.2. Reagent Addition and Fixation

1. Open the sample bottle and add the specified number of drops of Manganous Sulfate Solution.
2. Immediately add the specified number of drops of Alkaline Iodide-Azide Reagent.
3. Cap the bottle and invert several times to mix. A flocculent precipitate will form.
4. Allow the precipitate to settle for a few minutes until a clear supernatant forms above the precipitate.
5. Add the specified amount of Sulfuric Acid (or other acid reagent as per instructions). Cap and invert to mix until the precipitate dissolves, forming a yellowish-brown solution. This step fixes the oxygen.

3.3. Titration

1. Transfer a measured volume of the fixed sample (e.g., 20 mL) into the titration tube.
2. Add the specified PERMACHEM Reagent Powder Pillow contents to the sample in the titration tube. Mix to dissolve.
3. Slowly add the titrant (e.g., Sodium Thiosulfate Solution) drop by drop from the dropper bottle, swirling the tube after each drop.
4. Continue adding drops until the yellowish-brown color just disappears and the solution becomes colorless. This is the endpoint.
5. Count the number of drops used. Each drop typically corresponds to a specific concentration of dissolved oxygen (e.g., 1 drop = 1 mg/L DO). Refer to your kit's specific conversion factor.

3.4. Result Interpretation

The number of drops of titrant used directly corresponds to the dissolved oxygen concentration in mg/L (parts per million, ppm). Consult the specific instructions or conversion chart provided with your kit for accurate interpretation.

4. Maintenance and Storage

• Cleaning: Rinse all glassware and plasticware thoroughly with distilled or deionized water after each use. Allow to air dry.
• Reagent Storage: Keep all reagent bottles tightly capped when not in use to prevent contamination and degradation. Store the entire kit in a cool, dry place, away from direct sunlight and extreme temperatures.
• Expiration Dates: Pay attention to the expiration dates on reagents. Expired reagents can lead to inaccurate results. Dispose of expired reagents according to local regulations.
• Kit Integrity: Periodically inspect the carrying case for damage. Ensure all components are securely stored to prevent breakage or spills during transport.

5. Troubleshooting

6. Specifications

7. Warranty and Support

Specific warranty information for the Hach 146900 Dissolved Oxygen Test Kit is typically provided at the point of purchase or within the product packaging. For detailed warranty terms, technical support, or to order replacement parts and reagents, please contact Hach customer service directly or visit their official website.

Hach Company Contact Information: Please refer to the contact details provided on the Hach official website or product packaging for the most current support options.