The Koehler K27550 Automatic Petroleum Refractometer uses precision optics and superior image analysis to extend the repeatability and accuracy of refractive index measurements for petroleum products. Subjectivity is removed from tests results because no manual activities such as aligning shadowlines or reading analog scales are necessary. Opaque hydrocarbons present no problem for this unit which uses reflected light measurement technology as opposed to manual refractometers which are of the transmission type.

*** Can be coupled with the density meter (to get specific gravity) ***

The refractometer incorporates numerous innovations designed to improve the accuracy of petroleum product testing. A linear scanned diode array shadowline sensor is sensitive enough to read even the most demanding samples. A 589 nanometer filter gives true Sodium D-Line refractive index readings. A built-in twin Peltier heating and cooling system gives the instrument the capability of reading at up to 100°C without the need for an accessory water bath. The large graphical LCD is easy to read and provides complete sample analysis documentation including the reading, temperature and scale name of the screen. Documentation is also output through an RS232C serial port for export to either a PC or a parallel port to a standard printer. The instrument has an on-board data card for record storage. Optional Refractometer Communication Software package provides real-time output directly into Microsoft Excel.

Set-up, diagnostic and calibration routines are displayed with easy to follow step-by-step instructions. User-developed customer calibration curves may be programmed allowing automatic temperature correction, direct percent concentration, percent reaction completion, etc. This unit has been used successfully throughout the petrochemical industry.

Specifications
Conforms to the specifications of: ASTM D1218, D1747, D5006, D5775

Measurement Scales:
Refractive Index (RI)
BRIX (% sucrose)
Temperature Corrected RI
Temperature Corrected BRIX
Ten User-Programmable Scales

Illumination: 589nm light emitting diode with interference filter (estimated life: 100,000 hrs)

Range:
Dissolved Solids: 0 to 95% solids
Refractive Index: 1.29000 to 1.70000nD
(nD - Sodium D-Line Refractive Index)

Readability:
0.01% Solids 0.00001nD

Precision:
Refractive Index Standard Oils ± 0.00003
Typical clear aqueous samples, % Solids Temperature Compensated, as sucrose ±0.03%

Calibration Fluid: refractive index standard oil, NIST traceable nominal value 1.495 RI, 67.61 BRIX

Sample Types: Transparent, translucent or opaque

Prism Assembly: Stainless steel, synthetic sapphire sealed with solvent-resistant epoxy

Calibration:
1 point - Water only
2 point - Water and refractive index or Brix standard

Refractive index is a fundamental physical property that is used in conjunction with other properties to characterize pure hydrocarbons and their mixtures. It is a useful property for concentration measurements, purity determinations and chemical identification.

Features and Benefits
- Conforms to ASTM D1218, D1747, D5006, and D5775 test specifications
- Electronic heating and cooling twin Peltier system operates from 10 to 100°C, eliminating the need for a circulating water bath
- Automated and precise refractive index measurements
- Rugged sapphire prism
- Designed for samples ranging from clear to highly colored, dark and opaque
- Measures to the fifth decimal place refractive index or hundredths place in percent solids
- Clear graphical LCD display with on-screen instructions and full menu operation
- Multipoint calibration routines maximize accuracy
- Countdown timer insures consistent sample equilibration times
- RS232C communication ports