Hanna Instruments HI96832 Digital Refractometer for Propylene Glycol Analysis

The HI96832 Digital Refractometer uses refractive index measurement to ascertain the percent volume and freezing points of solutions based on propylene glycol. Glycol chillers and dispensing systems made for use in culinary applications, such beer and wine, employ propylene glycol. In glycol chillers, it’s crucial to maintain the proper proportion of glycol since an improper percentage can cause the system to freeze and burst, while an excessive amount will decrease the system’s efficiency.

The device transforms a sample’s refractive index to percentage volume or freezing point. These conversions are based on accepted worldwide standards for temperature compensation and unit conversion for glycol solutions (e.g. CRC Handbook of Chemistry and Physics, 87th Edition). On the factory floor or in the lab, the HI96832 is a simple-to-use instrument for calculating the freezing point and percent volume of propylene glycol solutions.

• Designed for propylene glycol analysis
• Automatic Temperature Compensation
• 0 – 100% Volume range with ±0.3% accuracy
• 0 to -50 ^°C freezing point range with ±0.5 ^°C accuracy

Measurement Units

Freezing point is displayed as a temperature from 0.0 to -51.0 ^°C corresponding to 0-60 % by volume. When the display shows “LO”, the freezing point is at a minimum (below -51 ^°C).

Making a Standard Solution

To make an X % Propylene Glycol Solution, follow the procedure below:

• Place container (such as a glass vial or dropper bottle that has a cover) on an analytical balance.
• Tare the balance.
• volumetrically add X mL of high purity propylene glycol (CAS #: 57-55-2; MW 76.09) to a 100 mL Grade A volumetric flask.
• Use distilled or deionized water to bring the flask close to the total volume, mix, allow the solution to return to room temperature.
• Once the solution has returned to room temperature use distilled or deionized water to bring the total volume to 100 mL. Mix solution well before use.