Understanding PolarimetersPolarimeters are precise optical instruments that measure purity and concentration through the optical activity exhibited in inorganic and organic compounds. Compounds are considered to be optically active if linearly polarized light is rotated when passing through them. This optical rotation in general means that the polarization of the direction of light is rotated at a specific angle proportionate to the concentration of the optically active substance being tested.

Optical rotation is measured in degrees of angle. At point zero, a polarizer and analyzer are set in an angle of 90 degrees toward each other, which means that no light reaches the detector (0% transmission). When an optically active substance is then placed in the measuring tube, the transmission will rise as a result of the plane polarization. To measure the angle, the analyzer is rotated up to the point where the transmission of the detector is again at minimum.

Polarimetry is a mature technique and today’s automatic instrumentation provides features and benefits that purely manual-optical systems do not. Busy labs processing multiple samples have the option of automated data capture, variable wavelength and temperature with circular polarimeters having 0.005 accuracy and 0.001 resolution. These instruments are suited for quality control, process control, and research for demanding applications in many industries including beverage, cosmetic, chemical, food, essential oils and pharmaceutical.

Which Polarimeter is Right for Your Lab?With this overview, Reichert makes it easy to determine which polarimeter suits your needs. Identify answers to the steps below to determine the specific requirements of your applications, in your industry, and with your budget. And then, simply pick the appropriate Reichert polarimeter from the chart on the back.

Polarimeter Buyer’s Guide

Selecting the Right Polarimeter

1 Measurement Range and AccuracyPurchasing a new polarimeter is a major decision. Choose the model that offers the best measurement range and accuracy to meet present and future application needs. Be aware that many polarimeters offer a very limited measurement range that may limit readings. Also, most importantly, there are many polarimeters on the market that have a non-linear accuracy specification. In other words, within the limited measurement range of these instruments, the accuracy specification can degrade to different levels across that range.

2 Measurement Response Time In today’s labs, speed is critical - with fewer resources processing more samples, technicians wait time must be minimized. Reichert offers the fastest measurements for a given accuracy.

3 Illumination Method Polarimeters use different lamp sources for transmitting polarized light. Some models employ halogen lamps which have a short life span, generate heat, and require servicing while others have LED illumination. LED illumination does not require maintenance or generate heat and is environmentally friendly and energy efficient. All Reichert polarimeters feature LED illumination.

4 MaintenanceOperating costs are important to consider when evaluating instruments. Many companies offer expensive service plans. Reichert builds robust instruments that provide reliable service for decades without requiring repair contracts. Backed by longstanding knowledge in the analytical instruments industry, Reichert polarimeters are manufactured for reliability and longevity.

5 Sample Tube Lengths, Material CompositionPolarimetric applications utilize different sample tube lengths. Longer tube lengths provide greater accuracy. But sometimes shorter tube lengths are needed if samples are limited in quantity or very expensive. Tube lengths range from 10 to 200mm depending on the application. Material composition of tubes is also important. Many sample types work well with a stainless steel tube. Samples that are corrosive are better suited for glass. Reichert provides a wide range of tube lengths and materials to meet all needs.

6 Software When selecting a polarimeter, ensure the software features meet your needs. Reichert offers an intuitive, simple interface for quickly and accurately attaining measurements. The measurement screens are simplified and Reichert software provides custom scales and methods, and is compliant with 21CFR Part 11 compliance.

Be sure the polarimeter has an accurate linear response over the entire measurement range.

Competitor’s polarimeters accuracy can degrade over a limited measurement range.

Reichert polarimeters are full range instruments, with an accurate linear response over the entire 3600 degree range.

Competitor

Accuracy range +900 to-900

Accuracy range +3600 to-3600

Reichert

Reichert Polarimeters

Technical Specifications

Polar1 - #10836-576 Polar2 - #10836-572 Polar3 - 10836-568

Measurement Scales Optical Rotation, Specific Rotation, 0Z International Sugar Scale, % Concentration

User Definable Scales 7 1,000 1,000

Measuring Range ± 3600 / ± 2590Z ±900 / ±2590Z ± 3600 / ± 2590Z

Resolution 0.010 / 0.020Z 0.0010 / 0.010Z 0.0010 / 0.010Z

Accuracy ± 0.010 / ± 0.030Z ± 0.0050 / ± 0.0150Z

Reproducibility ± 0.010 / ± 0.030Z ± 0.0050 / ± 0.0150Z

Sensitivity Up to OD 2 Up to OD 5

Wavelengths 589nm standard 589nm standard, others on request

Response Time 6 to 8 sec. over the entire measuring range ≤ 4 sec. over entire measuring range

Tube lengths 10 to 200 mm length Up to 100mm length 10 to 200 mm length

Tube Materials Glass, acid-proof stainless steel, stainless steel with temperature sensor

Temperature Interface

Temperature measurement NTC Sensor

Accuracy ± 0.030C ±0.10C ± 0.030C

Temperature range 00C to 990C 100C to 400C 00C to 990C

Resolution 0.010C

Other Information

Light Source LED

Display LCD display, monochromatic 4.3" color touchscreen 7" color touchscreen

Universal Display (optional) Universal Display (optional)

Interfaces RS232 (2x), Parallel (1x) RS232, USB, Ethernet RS232 (1x), USB A (4x), USB B (1x),

Ethernet

Dimensions 25.5 x 12.4 x 6.2 inches 17 x 12 x 6.3 inches 28.75 x 14.5 x 6.3 inches

(650 x 315 x 160mm) (430 x 300 x 160mm) (730 x 370 x 160 mm)

Weight 26lbs. (11.8kg) 22lbs. (9.97kg) 40 lbs. (18.3kg)

Polar1 Polar2 Polar3

For more information contact your VWR representative or visit VWR.com®