Portable Refractometer

Refractometer

Professional clinical refractometer with automatic temperature compensation for accurate measurement of protein, specific gravity, or BRIX content. Features precision optics with focusing eyepiece and built-in calibration adjustment.

Two Models Available

• CTL-REFM-PRSG: Protein / Specific Gravity Refractometer
• CTL-REFM-BR32: BRIX Refractometer

Specifications

Physical Specifications

Features

• Built-in automatic temperature compensation ranging from 10 degrees C to 30 degrees C (50 to 86 degrees F)
• Adjustable focusing eyepiece for clear scale viewing
• Hinged cover plate for sample application
• Calibration screw with included screwdriver
• Precision prism surface for accurate readings
• Protective storage case included

Operation - CTL-REFM-PRSG Model

Lift the cover plate and add 1 or 2 drops of urine or serum (or plasma) depending on which test is desired. Lower the cover plate and lightly press to ensure the liquid is evenly distributed across the prism. Read the value of the protein concentration (for serum or plasma) or specific gravity (for urine) from the appropriate scale by reading the boundary line between the light and dark area as it intersects the scale.

Operation - CTL-REFM-BR32 Model

Lift the cover plate and add 1 or 2 drops of liquid, such as wine, fruit juice, or other liquids containing sugar. Lower the cover plate and lightly press to ensure the liquid is evenly distributed across the prism. Read the percentage of sugar content from the percentage scale by reading the boundary line between the light and dark area as it intersects the scale.

Applications - BRIX Model

Testing quality of Colostrum for feeding young calves (CTL-REFM-BR32): Use 1 or 2 drops of colostrum following standard operating instructions. Research indicates that BRIX scores of 22% or higher represent good quality in colostrum, 18-21% represent colostrum that can be used for second feedings, and scores below 17% will need to be supplemented.

Testing total solids in milk for feeding older calves (CTL-REFM-BR32): Use 1 or 2 drops of milk following standard operating instructions. The expected content of total solids in normal milk would be 12.5% to 13%. The following equation was developed by Penn State to convert BRIX reading to total solids in milk:

TOTAL SOLIDS = (0.9984 x BRIX reading) + 2.077

Therefore, a BRIX reading of 10.4% equals 12.5% total solids, and a reading of 10.9% equals 13% total solids.

Calibration

Prior to inserting a sample, aim the front of the refractometer toward a bright indoor light source. Adjust the focusing eyepiece ring until the graduations on the scale can be clearly seen through the eyepiece. Lift the cover plate and add 1 or 2 drops of distilled water on the surface of the prism. Lower the cover plate, making sure that the water covers the entire surface of the prism. View the scale through the eyepiece and, using the enclosed small screwdriver, turn the adjustment screw to make the light/dark boundary coincide (meet) at the "W" at the bottom of the protein scale (Protein / SG model) or at the 0 % mark (BRIX model). Using a soft cotton cloth or absorbent paper, clean and dry the prism before measuring the first specimen.

Maintenance and Cautions

• Always treat specimen samples as though they were infectious
• Keep the refractometer horizontal when looking into the eyepiece to prevent sample dripping
• Clean the refractometer between samples and after use
• After use, clean with distilled water only; rinse and dry the glass and metal parts
• Store the refractometer in its case in a clean, cool, dry, non-corrosive atmosphere
• Handle the hinged cover plate carefully to avoid breaking the hinge
• When calibrating, ensure distilled water and specimens are at the same temperature
• If temperature varies greatly, adjust calibration every 30 minutes
• Never immerse the refractometer in water
• Use extra caution when cleaning to avoid scratching the prism
• Avoid dropping or strong shocks