Atago 2491 Master-S/Mill (Alpha) Hand-Held Salinity Refractometer User Manual

1. Introduction

The Atago 2491 MASTER-S/Millα (alpha) is a handheld, portable, water-resistant refractometer designed for measuring salinity and specific gravity. It features a salinity scale ranging from 0 to 100% and specific gravity from 1.000 to 1.070 with Automatic Temperature Compensation (ATC). Housed in a durable Ingress-Protection (IP)-65 rated polybutylene terephthalate (PBT) plastic body, this instrument is ideal for various applications including culinary, food and beverage, pharmaceutical, and water-testing industries.

This manual provides essential information for the proper use, care, and maintenance of your Atago 2491 Master-S/Millα refractometer.

Figure 1: Atago 2491 Master-S/Mill (Alpha) Hand-Held Salinity Refractometer. This image shows the sleek black body of the refractometer, highlighting its prism and eyepiece, designed for ease of use and durability.

2. Package Contents and Setup

2.1 What's in the Box?

Upon opening the package, please verify that all the following items are included:

• Atago 2491 MASTER-S/Millα Refractometer
• Calibration Screwdriver
• Plastic Storage Case
• Instruction Manual (this document)

2.2 Initial Setup

No complex assembly is required for the Atago 2491 Master-S/Millα. Simply remove the refractometer from its protective plastic storage case. Ensure the prism surface is clean before first use. The unit operates using ambient light and does not require batteries or an external power source.

3. Operating Instructions

The Atago 2491 Master-S/Millα is designed for straightforward operation. Follow these steps for accurate measurements:

1. Prepare the Sample: Ensure your sample is well-mixed and free of large particles.
2. Apply the Sample: Using the spoon-shaped tip, apply a small portion (10θl or more) of the sample onto the prism surface. The Automatic Sample Distribution (ASD) feature will spread the sample evenly.
3. View the Reading: Point the refractometer towards a natural light source (e.g., a window) or a bright lamp. Look through the monocular, cushioned eyepiece.
4. Focus (if necessary): Adjust the focus of the eyepiece until the scale and the boundary line are clear and sharp.
5. Read the Measurement: The analog salinity scale features a bright, high-contrast display. Read the measurement where the boundary line intersects with the memory line. The unit displays results in parts per million (%).
6. Automatic Temperature Compensation (ATC): The refractometer automatically compensates for temperature variations between 10 to 30 degrees Celsius, providing immediate and accurate readings without manual adjustments.
7. Clean After Use: Immediately after each measurement, clean the prism and sample stage as described in the Maintenance section to prevent residue buildup.

4. Maintenance

Proper maintenance ensures the longevity and accuracy of your refractometer.

4.1 Cleaning

• The refractometer's body is IP-65 rated, protecting it against dust and water jets (excluding the eyepiece). This allows for easy cleaning.
• After each use, clean the prism and sample stage thoroughly with a soft, damp cloth or by rinsing under running water from a faucet.
• Ensure no residue remains on the prism, as this can affect measurement accuracy.
• The ridged outer shell is designed for easy cleaning, reducing the possibility of food and sample entrapment and preventing bacterial growth.
• Do not immerse the entire unit in water, especially the eyepiece.
• Dry the unit completely before storing it in its plastic storage case.

4.2 Calibration

Calibration ensures the accuracy of your refractometer. It can be controlled and adjusted using the exposed calibration screw.

• Use the included specialized screwdriver to adjust the calibration screw. Other small, flat-head tools may also be used.
• Refer to specific calibration procedures for your application, typically involving distilled water or a known standard solution.
• Even after adjusting the calibration screw, the unit retains its water-resistance.

5. Troubleshooting

If you encounter issues with your refractometer, consider the following common solutions:

• Unclear or Blurry View: Ensure the eyepiece is properly focused. Adjust the focus by rotating the eyepiece. Also, ensure sufficient ambient light is illuminating the scale.
• Inaccurate Readings:
  • Cleanliness: The most common cause of inaccuracy is a dirty prism. Thoroughly clean the prism and sample stage.
  • Calibration: The unit may require recalibration. Follow the calibration steps in Section 4.2.
  • Sample Volume: Ensure at least 10θl of sample is applied to cover the prism surface adequately.
  • Temperature: While the unit has ATC, extreme temperatures outside the 10 to 30 degrees C range may affect accuracy. Allow the unit and sample to acclimate to room temperature if possible.
• Boundary Line Not Visible: Ensure enough sample is applied and that the refractometer is pointed towards a strong, consistent light source.

If problems persist, contact Atago customer support for further assistance.

6. Specifications

Detailed technical specifications for the Atago 2491 Master-S/Millα refractometer:

7. Warranty Information

The Atago 2491 Master-S/Millα refractometer comes with a Limited One-Year Warranty from the date of purchase. This warranty covers manufacturing defects under normal use. Please retain your proof of purchase for warranty claims. For specific terms and conditions, refer to the warranty card included with your product or contact Atago customer support.

8. Customer Support

For technical assistance, service, or inquiries regarding your Atago product, please contact Atago Co., Ltd. Atago manufactures analytical instruments such as refractometers, polarimeters, and saccharimeters, adhering to high-quality standards including HACCP, GMP, GLP, and various ISO standards. Contact information can typically be found on the official Atago website or on the product packaging.