Refractometer-Rudolph’s Digital J57HA Heavy Use, High Accuracy, QC Instrument for Food Quality Testing.
The Rudolph J57HA refractometer was designed to meet the unique needs of food quality testing where the automatic refractometer is viewed as a quality control (QC) tool rather than a laboratory instrument. A single flat measurement surface, automatic electronic temperature control, and one button measurement capability make it perfect for heavy use food industry applications, where fast, automatic, and accurate Brix readings are required.


Automatic Measuring System

The Rudolph J57HA features a fully automatic measuring system. The operator simply places the sample on the prism, presses a button and the results are displayed on 7.5cm x 10cm back lit LCD. There are no shadow lines to match and there is no eyepiece requiring operator determination or manual adjustment.


Automatic Refractometer with Electronic Temperature Control

BRIX readings are very sensitive to temperature changes while food industry samples tend to arrive at the refractometer either very hot or very cold. Temperature related variations in BRIX readings can be minimized by using the ICUMSA temperature correction for sucrose, but only minimized, not eliminated. The ICUMSA Temperature Correction Table was developed for a sucrose and water solution and the further from pure sucrose and water the sample is, the more inaccurate Temperature Correction becomes. Temperature Correction also requires that the sample temperature remains stable during the measurement. So a room temperature sugar solution measurement works reasonably well, but if a sauce sample or syrup comes from a kettle or a refrigerator, temperature correction will be almost useless. The solution to measuring hot samples has always been to control the sample temperature with a circulating water bath and then clean and maintain the water bath. This is still not ideal as bringing samples to temperature with a water bath is slow and maintaining a water bath is time consuming. The J57HA’s refractometer addresses this issue with a built in, maintenance free, electronic temperature control which provides the best solution for these real world problems: absolute accuracy regardless of sample type and excellent thermo stability no matter what the sample or environmental temperatures are.


Easy to Clean Measurement Surface

Regardless of the specified instrument accuracy the real world performance will always depend on how well the instrument is cleaned between samples. The J57HA refractometer addresses this issue by providing a very flat easy to clean measurement surface with no corners or crevices that tend to trap sugars, syrups, and other food industry samples.


High Durability Sapphire Prism

When a traditional automatic refractometer is used in a high throughput application, prism replacement becomes a regular task. This is because traditional Abbe refractometers have glass prisms which are much softer than the sapphire prism of the rugged J Series refractometers and thus more prone to scratching and general wear and tear which can result in inaccurate readings potentially unknown to the operator.


Lower Cost of Use over ABBE Refractometers

Traditional industry has used an ABBE refractometer either with or without a water bath. The cost of replacing the water bath and the Abbe dual glass prism over time makes the cost of owning a Rudolph Research J57HA with its single sapphire prism and electronic temperature control, actually less than the cost of an Abbe over their comparable useful lives. The speed and accuracy of readings also increases productivity and reduces costly mistakes that can be potentially caused by inaccurate readings.



The J57HA Automatic Refractometer offers 1 or 2 point calibration. The instrument stores the date and the time of the last calibration in line with ISO and similar standards. Regardless of how many times the refractometer is calibrated it can always be restored to the default factory calibration.


Touchscreen and Digital LCD

All functions of the J57HA Automatic Refractometer are activated through a large digital, touch screen LCD. The 70mm X 75mm measure button on the J57HA is designed to allow an operator wearing gloves to activate measurement with an elbow or side of a hand. The sealed touchscreen is resistant to fingernails, sharp objects, chemicals and acids.

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