Designed as a research quality instrument the Rudolph J357 Digital, Bench-top Refractometer has the highest performance of any refractometer in the Rudolph range. This instrument offers the same extra wide RI measurement range as our chemical industry refractometer models combined with the high accuracy of our food industry refractometer models. It also offers the most powerful automatic temperature control (heating and cooling) and is able to make RI and BRIX measurements at up to 120 °C.
Operating the J357 is as simple as placing a sample on the artificial sapphire prism, closing the presser and reading the answer on the Digital Display -- all in just a few seconds. There are no shadow lines to match and there is no eyepiece requiring any kind of operator determination or manual adjustment, the J357 is a fully Automatic Refractometer.. When the "measure when stable mode" is selected, the J357 Refractometer automatically waits until the sample has been heated or cooled to a predefined temperature before initiating a measurement.
Unlike other temperature controlled refractometers, the J357 has temperature control from both above and below the sample. The sample cover is controlled to the same temperature as the prism and, when lowered, is designed to provide a temperature controlled micro environment that provides unrivaled temperature stability, fast measurement time and minimal evaporation. With the Auto Measure option, the sample cover can also be used to initiate measurement.
The Rudolph J357 is available with an optional Temperature Controlled Sample Presser that touches the sample. Compared with the standard temperature controlled cover, the optional presser reduces the empty volume of the measurement area thereby decreasing evaporation and at the same time helping to evenly spread semi solid materials over the measurement prism. This feature offers improved performance on many samples.
The J357 offers 1 point, 2 point or a full multi-point calibration. Calibration can be done at 20°C, 25°C or any user selectable temperature within the available range. Regardless of how many times the refractometer has been calibrated, it can always be restored to the initial factory calibration if required.
The J357 Refractometer is available with 100 possible programmable scales. Custom scales can be set up in a few minutes. Simply enter 2, 6 or 10 data points of concentration and corresponding RI (refractive index) value, press Compute and the instrument creates a new custom scale.
The J series refractometer offers a sapphire prism for high mechanical and chemical durability. The sample well is acid resistant 316 stainless steel with a techtron sealing ring. There is no lamp to change, the LED light source is guaranteed for 1,000,000 measurements.
No matter how good a refractometer is, accurate results will only be obtained if the instrument is clean. The Rudolph J Series offers a flat, easy to clean prism that makes this process simple even with sticky samples like sugars, syrups, and petrochemicals.
Rudolph's J357 refractometer is available with data storage on a removable media card. In 21 CFR mode the data storage system provides a secure password system for storing raw data to comply with FDA specifications. When using non 21 CFR 11 mode the data storage system is a powerful tool for kinetics experiments and excellent system for QA traceability and to help laboratories meet the requirements of ISO and similar quality systems.
A large 7.5cm x 10cm cold cathode florescent back lit graphics, digital LCD allows the scale, sample temperature, set temperature, air temperature, time, date and temperature correction status to be easily viewed. All functions are activated through a touchscreen panel which will not wear out or be misplaced like traditional or detachable keypads. The digital touchscreen is resistant to fingernails, sharp objects, chemicals, and acids.
Having Rudolph’s J357 fully automatic electronic temperature control means:
In 21 CFR Part 11 mode, all measurements are written to a secure data storage card. Who used the instrument, what they measured and when it was measured is permanently stored on a locked storage media. The media card can also be used to transfer records to a computer for redundancy or "backup" purposes.
Rudolph Research Analytical manufactures automatic, digital, bench-top refractometers for a wide variety of industries. With over 5,000 laboratory instruments installed in demanding applications worldwide and thousands still in use that were manufactured in the 70s, 80s, and 90s, Rudolph has established itself as a premier vendor well known for its quality and reliability. Rudolph has also consistently set the pace for innovative design and features that bring new and important functionality to its market leading line of refractometers. Our service and responsiveness come from a deep commitment to serving our customers with integrity, quality and innovation that we have maintained for over 50 years. Please read one of our customer testimonials.